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 A144451 Triangle A(n,k) read by rows: A(n,1)=A(n,n)=1 and A(n,k) = A(n-2,k-1) - 2*A(n,k-1) + 1 for 1
 1, 1, 1, 1, 0, 1, 1, 0, 2, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 2, -3, 8, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, -4, 17, -32, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,9 COMMENTS Row sums are 1, 2, 2, 4, 3, 4, 4, 10, 5, -14, 6, 128, 7, -720, 8, 4630, 9, -30194, 10, ... LINKS FORMULA A(n,k) = A(n-2,k-1) - 2*A(n,k-1) + 1. EXAMPLE 1; 1, 1; 1, 0, 1; 1, 0, 2, 1; 1, 0, 1, 0, 1; 1, 0, 1, 1, 0, 1; 1, 0, 1, 0, 1, 0, 1; 1, 0, 1, 0, 2, -3, 8, 1; 1, 0, 1, 0, 1, 0, 1, 0, 1; 1, 0, 1, 0, 1, 1, -4, 17, -32, 1; MAPLE A144451 := proc(n, k)     option remember;     if k < 1 or k > n then         0 ;     elif n = 1 or n=k then         1;     else         procname(n-2, k-1)-2*procname(n, k-1)+1 ;     end if; end proc: # R. J. Mathar, Jul 21 2015 MATHEMATICA A[n_, 1] := 1; A[n_, n_] := 1; A[n_, k_] := A[n, k] = A[n - 2, k - 1] - 2*A[n, k - 1] + 1; a = Table[A[n, k], {n, 10}, {k, n}]; Flatten[a] CROSSREFS Sequence in context: A276004 A133300 A178779 * A259287 A090464 A277967 Adjacent sequences:  A144448 A144449 A144450 * A144452 A144453 A144454 KEYWORD tabl,sign,easy AUTHOR Roger L. Bagula and Gary W. Adamson, Oct 06 2008 STATUS approved

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Last modified September 15 04:09 EDT 2019. Contains 327062 sequences. (Running on oeis4.)