OFFSET
0,6
FORMULA
EXAMPLE
MAPLE
A009766 := proc(n, k) if k<0 or k >n then 0; else binomial(n+k, n)*(n-k+1)/(n+1) ; end if; end proc:
A000108 := proc(n) binomial(2*n, n)/(n+1) ; end proc:
A176239 := proc(n, k) if k <= 2*n-1 then (-1)^(n+k+1)*A009766(n, k-n+1) elif k = 2*n then 0; elif k < 2*(n+1) then (-1)^(n+1)*A000108(n+1); else 0; end if; end proc: # R. J. Mathar, Dec 03 2010
CROSSREFS
KEYWORD
tabf,sign
AUTHOR
Paul Curtz, Apr 12 2010
STATUS
approved