OFFSET
0,3
FORMULA
a(n) = sum |C(n,k+1)-C(n,k)|, k=0..n-1 = 2*sum C(n,k+1)-C(n,k), k=0..floor((n-1)/2) = 2*(C(n, floor((n+1)/2)) - 1)
PROG
(Maxima) A218008(n):=2*(binomial(n, floor((n+1)/2))-1)$
makelist(A218008(n), n, 0, 30); /* Martin Ettl, Nov 01 2012 */
CROSSREFS
KEYWORD
nonn
AUTHOR
Olivier Gérard, Oct 18 2012
STATUS
approved