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 A108299 Triangle read by rows, 0 <= k <= n: T(n,k) = binomial(n-[(k+1)/2],[k/2])*(-1)^[(k+1)/2]. 57
 1, 1, -1, 1, -1, -1, 1, -1, -2, 1, 1, -1, -3, 2, 1, 1, -1, -4, 3, 3, -1, 1, -1, -5, 4, 6, -3, -1, 1, -1, -6, 5, 10, -6, -4, 1, 1, -1, -7, 6, 15, -10, -10, 4, 1, 1, -1, -8, 7, 21, -15, -20, 10, 5, -1, 1, -1, -9, 8, 28, -21, -35, 20, 15, -5, -1, 1, -1, -10, 9, 36, -28, -56, 35, 35, -15, -6, 1, 1, -1, -11, 10, 45, -36, -84, 56, 70 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 0,9 COMMENTS Matrix inverse of A124645. Let L(n,x) = Sum(T(n,k)*x^(n-k): 0<=k<=n) and Pi=3.14...: L(n,x) = Prod(x - 2*cos((2*k-1)*Pi/(2*n+1)): 1<=k<=n); Sum(T(n,k): 0<=k<=n) = L(n,1) = A010892(n+1); Sum(abs(T(n,k)): 0<=k<=n) = A000045(n+2); abs(T(n,k))=A065941(n,k), T(n,k)=A065941(n,k)*A087960(k); T(2*n,k) + T(2*n+1,k+1) = 0 for 0<=k<=2*n; T(n,0)=A000012(n)=1; T(n,1)=-1 for n>0; T(n,2)=-(n-1) for n>1; T(n,3)=A000027(n)=n for n>2; T(n,4)=A000217(n-3) for n>3; T(n,5)=-A000217(n-4) for n>4; T(n,6)=-A000292(n-5) for n>5; T(n,7)=A000292(n-6) for n>6; T(n,n-3)=A058187(n-3)*(-1)^[n/2] for n>2; T(n,n-2)=A008805(n-2)*(-1)^[(n+1)/2] for n>1; T(n,n-1)=A008619(n-1)*(-1)^[n/2] for n>0; T(n,n) = L(n,0) = (-1)^[(n+1)/2]; L(n,1) = A010892(n+1); L(n,-1) = A061347(n+2); L(n,2) = 1; L(n,-2) = A005408(n)*(-1)^n; L(n,3) = A001519(n); L(n,-3) = A002878(n)*(-1)^n; L(n,4) = A001835(n+1); L(n,-4) = A001834(n)*(-1)^n; L(n,5) = A004253(n); L(n,-5) = A030221(n)*(-1)^n; L(n,6) = A001653(n); L(n,-6) = A002315(n)*(-1)^n; L(n,7) = A049685(n); L(n,-7) = A033890(n)*(-1)^n; L(n,8) = A070997(n); L(n,-8) = A057080(n)*(-1)^n; L(n,9) = A070998(n); L(n,-9) = A057081(n)*(-1)^n; L(n,10) = A072256(n+1); L(n,-10) = A054320(n)*(-1)^n; L(n,11) = A078922(n+1); L(n,-11) = A097783(n)*(-1)^n; L(n,12) = A077417(n); L(n,-12) = A077416(n)*(-1)^n; L(n,13) = A085260(n); L(n,14) = A001570(n); L(n,-14) = A028230(n)*(-1)^n; L(n,n) = A108366(n); L(n,-n) = A108367(n). Row n of the matrix inverse (A124645) has g.f.: x^[n/2]*(1-x)^(n-[n/2]). - Paul D. Hanna, Jun 12 2005 From L. Edson Jeffery, Mar 12 2011: (Start) Conjecture: Let N=2*n+1, with n>2. Then T(n,k) (0<=k<=n) gives the k-th coefficient in the characteristic function p_N(x)=0, of degree n in x, for the n X n tridiagonal unit-primitive matrix G_N (see [Jeffery]) of the form G_N=A_{N,1}= (0 1 0 ... 0) (1 0 1 0 ... 0) (0 1 0 1 0 ... 0) ... (0 ... 0 1 0 1) (0 ... 0 1 1), with solutions phi_j=2*cos((2*j-1)*Pi/N), j=1,2,...,n. For example, for n=3, G_7=A_{7,1}= (0 1 0) (1 0 1) (0 1 1). We have {T(3,k)}=(1,-1,-2,1), while the characteristic function of G_7 is p(x)=x^3-x^2-2*x+1=0, with solutions phi_j=2*cos((2*j-1)*Pi/7), j=1,2,3. (End) The triangle sums, see A180662 for their definitions, link A108299 with several sequences, see the crossrefs. - Johannes W. Meijer, Aug 08 2011 The roots to the polynomials are chaotic using iterates of the operation (x^2 - 2), with cycle lengths L and initial seeds returning to the same term or (-1)* the seed. Periodic cycle lengths L are shown in A003558 such that for the polynomial represented by row r, the cycle length L is A003558(r-1). The matrices corresponding to the rows as characteristic polynomials are likewise chaotic [Cf. Kappraff et al., 2005] with the same cycle lengths but substituting 2*I for the "2" in (x^2 - 2), where I = the Identity matrix.  For example, the roots to x^3 - x^2 - 2x + 1 = 0 are 1.801937..., -1.246979..., and 0.445041...With 1.801937...as the initial seed and using (x^2 - 2), we obtain the 3-period trajectory of 8.801937...-> 1.246979...-> -0.445041...(returning to -1.801937...). We note that A003558(2) = 3.  The corresponding matrix M is: [0,1,0; 1,0,1; 0,1,1,]. Using seed M with (x^2 - 2*I), we obtain the 3-period with the cycle completed at (-1)*M. - Gary W. Adamson, Feb 07 2012 REFERENCES Friedrich L. Bauer, 'De Moivre und Lagrange: Cosinus eines rationalen Vielfachen von Pi', Informatik Spektrum 28 (Springer, 2005). Jay Kappraff, S. Jablan, G. Adamson, & R. Sazdonovich: "Golden Fields, Generalized Fibonacci Sequences, & Chaotic Matrices"; FORMA, Vol 19, No 4, (2005). LINKS Reinhard Zumkeller, Rows n = 0..150 of triangle, flattened Henry W. Gould, A Variant of Pascal's Triangle, Corrections, The Fibonacci Quarterly, Vol. 3, Nr. 4, Dec. 1965, p. 257-271. L. E. Jeffery, Unit-primitive matrices. Michelle Rudolph-Lilith, On the Product Representation of Number Sequences, with Application to the Fibonacci Family, arXiv preprint arXiv:1508.07894, 2015 FORMULA T(n,k) = binomial(n-[(k+1)/2],[k/2])*(-1)^[(k+1)/2]. T(n+1, k) = if sign(T(n, k-1))=sign(T(n, k)) then T(n, k-1)+T(n, k) else -T(n, k-1) for 0=0 is (u^(2*n+1) + v^(2*n+1))/(u + v), where u and v are defined by u^2 + v^2 = 1 and u*v = z. - Emeric Deutsch, Jun 16 2011 From Johannes W. Meijer, Aug 08 2011: (Start) abs(T(n,k)) = A065941(n,k) = abs(A187660(n,n-k)) T(n,n-k) = A130777(n,k); abs(T(n,n-k)) = A046854(n,k) = abs(A066170(n,k)). (End) EXAMPLE Triangle begins: 1 ; 1, -1 ; 1, -1, -1 ; 1, -1, -2, 1 ; 1, -1, -3, 2, 1 ; 1, -1, -4, 3, 3, -1 ; 1, -1, -5, 4, 6, -3, -1 ; 1, -1, -6, 5, 10, -6, -4, 1 ; 1, -1, -7, 6, 15, -10, -10, 4, 1 ; 1, -1, -8, 7, 21, -15, -20, 10, 5, -1 ; 1, -1, -9, 8, 28, -21, -35, 20, 15, -5, -1 ; 1, -1, -10, 9, 36, -28, -56, 35, 35, -15, -6, 1 ;... MAPLE A108299 := proc(n, k): binomial(n-floor((k+1)/2), floor(k/2))*(-1)^floor((k+1)/2) end: seq(seq(A108299 (n, k), k=0..n), n=0..11); # Johannes W. Meijer, Aug 08 2011 MATHEMATICA t[n_, k_?EvenQ] := I^k*Binomial[n-k/2, k/2]; t[n_, k_?OddQ] := -I^(k-1)*Binomial[n+(1-k)/2-1, (k-1)/2]; Table[t[n, k], {n, 0, 12}, {k, 0, n}] // Flatten (* Jean-François Alcover, May 16 2013 *) PROG (PARI) {T(n, k)=polcoeff(polcoeff((1-x*y)/(1-x+x^2*y^2+x^2*O(x^n)), n, x)+y*O(y^k), k, y)} (Hanna) (Haskell) a108299 n k = a108299_tabl !! n !! k a108299_row n = a108299_tabl !! n a108299_tabl = [1] : iterate (\row ->    zipWith (+) (zipWith (*) ([0] ++ row) a033999_list)                (zipWith (*) (row ++ [0]) a059841_list)) [1, -1] -- Reinhard Zumkeller, May 06 2012 CROSSREFS Cf. A049310, A039961, A124645 (matrix inverse). Triangle sums (see the comments): A193884 (Kn11), A154955 (Kn21), A087960 (Kn22), A000007 (Kn3), A010892 (Fi1), A134668 (Fi2), A078031 (Ca2), A193669 (Gi1), A001519 (Gi3), A193885 (Ze1), A050935 (Ze3). - Johannes W. Meijer, Aug 08 2011 Cf. A003558. Cf. A033999, A059841. Sequence in context: A136568 A152157 A039961 * A065941 A123320 A054123 Adjacent sequences:  A108296 A108297 A108298 * A108300 A108301 A108302 KEYWORD sign,tabl AUTHOR Reinhard Zumkeller, Jun 01 2005 EXTENSIONS Corrected and edited by Philippe Deléham, Oct 20 2008 STATUS approved

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Last modified October 15 09:22 EDT 2019. Contains 328026 sequences. (Running on oeis4.)