A131969 First differences of A020806.

3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6, 3, -2, 6, -3, 2, -6

Offset

0,1

Links

Table of n, a(n) for n=0..77.

Formula

a(n)=11*(-1)^n/3-2*A010892(n)/3+7*A010892(n-1)/3, n>0. a(n+6)=a(n). G.f.: (3-2x+6x^2)/((1+x)(1-x+x^2)). [From R. J. Mathar, Oct 24 2008]

Crossrefs

Sequence in context: A198930 A263353 A248945 * A058971 A186204 A137324

Adjacent sequences: A131966 A131967 A131968 * A131970 A131971 A131972

Keyword

sign

Author

Paul Curtz, Oct 06 2007

Status

approved