A115635 Periodic {1,1,-5,0,1,-3,-1,0,-3,1,-1,-4}.

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

Offset

0,3

Comments

Diagonal sums of number triangle A115633.

Links

Table of n, a(n) for n=0..71.

Index entries for linear recurrences with constant coefficients, signature (-1,-1,0,1,1,1).

Formula

G.f.: (1+2x-3x^2-4x^3-5x^4-4x^5)/((1-x^3)*(1+x+x^2+x^3)); a(n)=sum{k=0..floor(n/2), A115633(n-k, k)}.

Crossrefs

Sequence in context: A198927 A198100 A104112 * A019729 A261851 A117015

Adjacent sequences: A115632 A115633 A115634 * A115636 A115637 A115638

Keyword

easy,sign

Author

Paul Barry, Jan 27 2006

Status

approved