OFFSET
0,5
COMMENTS
Second column of number triangle A106180.
FORMULA
a(n) = sin(Pi*n/2)*(C((n-1)/2)*(1-(-1)^n)/2) + sin(Pi*(n+1)/2)*(C(n/2)*(1+(-1)^n)/2) - 0^n for n > 0.
Conjecture: (n+2)*a(n) + n*a(n-1) + 4*(n-1)*a(n-2) + 4*(n-3)*a(n-3) = 0. - R. J. Mathar, Nov 15 2011
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Apr 24 2005
STATUS
approved