login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A104597 Triangle T read by rows: inverse of Motzkin triangle A097609. 13
1, 0, 1, -1, 0, 1, -1, -2, 0, 1, 0, -2, -3, 0, 1, 1, 1, -3, -4, 0, 1, 1, 4, 3, -4, -5, 0, 1, 0, 3, 9, 6, -5, -6, 0, 1, -1, -2, 5, 16, 10, -6, -7, 0, 1, -1, -6, -9, 6, 25, 15, -7, -8, 0, 1, 0, -4, -18, -24, 5, 36, 21, -8, -9, 0, 1, 1, 3, -7, -39, -50, 1, 49, 28, -9, -10, 0, 1, 1, 8 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

0,8

COMMENTS

Riordan array ((1-x)/(1-x+x^2),x(1-x)/(1-x+x^2)). - Paul Barry, Jun 21 2008

LINKS

Table of n, a(n) for n=0..79.

D. Merlini, R. Sprugnoli and M. C. Verri, An algebra for proper generating trees

FORMULA

T(n,m) = sum(j=0..m, binomial(m,j)*sum(k=0..n, binomial(k,n-k)*(-1)^(n-k)*binomial(k+j-1,j-1))*(-1)^(m-j)). - Vladimir Kruchinin, Apr 08 2011

T(n,m) = sum(k=ceiling((n-m-1)/2)..n-m, binomial(k+m,m)*binomial(k+1,n-k-m)*(-1)^(n-k-m)). - Vladimir Kruchinin, Dec 17 2011

T(n,k) = T(n-1,k) + T(n-1,k-1) - T(n-2,k) - T(n-2,k-1), T(0,0) = T(1,1) = 1, T(1,0) = 0, T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Feb 20 2013

T(n+5,n) = (n+1)^2. - Philippe Deléham, Feb 20 2013

From Tom Copeland, Nov 01 and 04 2014: (Start)

O.g.f.: G(x,t) = Pinv[Cinv(x),t+1] = Cinv(x) / [1 - (t+1)Cinv(x)] = x*(1-x) / [1-(t+1)x(1-x)] = x + t * x^2 + (-1 + t^2) * x^3 + ..., where Cinv(x)= x * (1-x) is the inverse of C(x) = [1-sqrt(1-4*x)]/2, an o.g.f. for the Catalan numbers A000108 and Pinv(x,t) = -P(-x,t) = x/(1-t*x) is the inverse of P(x,t) = x/(1+x*t).

Ginv(x,t)= C[P[x,t+1]]= C[x/(1+(t+1)x)] = {1-sqrt[1-4*x/(1+(t+1)x)]}/2.

The inverse in x of G(x,t) with t replaced by -t is the o.g.f. of A091867, and G(x,t-1) is a signed version of the (mirrored) Fibonacci polynomials A030528. (End)

EXAMPLE

1

0,1

-1,0,1

-1,-2,0,1

0,-2,-3,0,1

1,1,-3,-4,0,1

1,4,3,-4,-5,0,1

0,3,9,6,-5,-6,0,1

-1,-2,5,16,10,-6,-7,0,1

-1,-6,-9,6,25,15,-7,-8,0,1

PROG

(Maxima)

T(n, m):=sum(binomial(m, j)*sum(binomial(k, n-k)*(-1)^(n-k)*binomial(k+j-1, j-1), k, 0, n)*(-1)^(m-j), j, 0, m); \\ Vladimir Kruchinin, Apr 08 2011

CROSSREFS

Row sums are A009116 with different signs.

Row sums are A146559(n). - Philippe Deléham, Feb 20 2013

Cf. A091867, A030528, A000108.

Sequence in context: A129447 A125079 A235987 * A182936 A072662 A030010

Adjacent sequences:  A104594 A104595 A104596 * A104598 A104599 A104600

KEYWORD

sign,tabl

AUTHOR

Ralf Stephan, Mar 17 2005

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified June 24 15:07 EDT 2017. Contains 288697 sequences.