A138569 First differences of A137776.

0, 1, 0, 1, 0, 1, 1, 0, 4, -2, 10, -4, 20, -4, 36, 0, 64, 8, 120, 16, 240, 16, 496, 0, 1024, -32, 2080, -64, 4160, -64, 8256, 0, 16384, 128, 32640, 256, 65280, 256, 130816, 0, 262144, -512, 524800, -1024, 1049600, -1024, 2098176, 0, 4194304, 2048, 8386560, 4096, 16773120

Offset: 0

Author

Paul Curtz, May 12 2008

Keywords

• sign

Links

• Index entries for linear recurrences with constant coefficients, signature (0, 4, 0, -6, 0, 4).

Crossrefs

Cf. A135356.

Formula

a(n)=4a(n-2)-6a(n-4)+4a(n-6), n>7.

a(2n)=A000749(n). a(2n+1)=(-1)^(n+1)*A009116(n-1), n>0.

O.g.f.: x(1-x)(x^4-2x^2+1+x-2x^3+2x^5)/((1-2x^2)(1-2x^2+2x^4)). - R. J. Mathar, Aug 02 2008

Extensions

Edited and extended by R. J. Mathar, Aug 02 2008