OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..750 (terms 0..100 from Vincenzo Librandi)
FORMULA
a(n) = T(2*n,n) where T(n,k) = A132276(n,k).
a(n) = Sum_{i=0..(n/2)} (binomial(n+2*i,i)*((n+1)/(i+n+1)) * Sum_{j=0..(n-2*i)} (binomial(2*n-j,n+2*i)*binomial(n-2*i-j,j) ).
MATHEMATICA
Table[Sum[Binomial[n+2i, i](n+1)/(i+n+1)Sum[Binomial[2n-j, n+2i]Binomial[n-2i-j, j], {j, 0, n-2i}], {i, 0, n/2}], {n, 0, 21}]
PROG
(Maxima) makelist(sum(binomial(n+2*i, i)*(n+1)/(i+n+1)*sum(binomial(2*n-j, n+2*i)*binomial(n-2*i-j, j), j, 0, n-2*i), i, 0, n/2), n, 0, 21);
(PARI) for(n=0, 30, print1(sum(i=0, n/2, binomial(n+2*i, i)*((n+1)/(i+n+1)) *sum(j=0, n-2*i, binomial(2*n-j, n+2*i)*binomial(n-2*i-j, j))), ", ")) \\ G. C. Greubel, Dec 28 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Emanuele Munarini, May 05 2011
STATUS
approved