OFFSET
0,2
COMMENTS
Hankel transform is 5^n . Second binomial transform is A076036 .
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
FORMULA
a(n)=Sum{k, 0<=k<=n} A053121(n,k)*A015521(k+1) = (-1)^n*A127363(n) . G.f.: (1/sqrt(1-4x^2))(1-xc(x^2))/(1-4x*c(x^2)), where c(x) is the g.f. of Catalan numbers A000108 .
Recurrence: 4*n*a(n) = (17*n-8)*a(n-1) + 2*(8*n+1)*a(n-2) - 68*(n-2)*a(n-3) . - Vaclav Kotesovec, Oct 20 2012
a(n) ~ 3*17^n/4^(n+1) . - Vaclav Kotesovec, Oct 20 2012
MATHEMATICA
Table[Sum[Binomial[n, Floor[k/2]]*(-1)^k*4^(n-k), {k, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Oct 20 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Philippe Deléham, Nov 26 2007
EXTENSIONS
More terms from Vincenzo Librandi, May 25 2013
STATUS
approved