OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..500
FORMULA
Differs from A072547 by -1, +1, -1, +1, -1, ... - Ralf Stephan, Apr 19 2004
Equals sum(m=0, n, (-1)^m*binomial(n+m, m)). - Henry Gould, Apr 23 2004
Let f(n) = (-1)^n a(n). Then 2f(n) + f(n-1) = (3n+1)C(n) + (-1)^n, where C(n) = (2n+1)!/n!(n+1)! is a Catalan number (A000108). - Henry Gould, Apr 24 2004
Recurrence: 2*(n+1)*(15*n^2 - 31*n + 12)*a(n) = -(5*n-3)*(15*n^2 - 19*n - 4)*a(n-1) + (165*n^3 - 266*n^2 - 11*n + 60)*a(n-2) - 2*(2*n-3)*(15*n^2 - n - 4)*a(n-3). - Vaclav Kotesovec, Sep 05 2014
CROSSREFS
KEYWORD
sign
AUTHOR
Francois Jooste (pin(AT)myway.com), Apr 23 2004
STATUS
approved