OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000 (terms 0..100 from Vincenzo Librandi)
FORMULA
a(n) = T(2*n,n), where T(n,k)=A190215(n,k).
a(n) = Sum_{i=0..n} binomial(n+i,n)*Sum_{j=0..n-i} binomial(i+j-1,j)*binomial(j,n-i-j).
MATHEMATICA
Table[Sum[Binomial[n+i, n]Sum[Binomial[i+j-1, j]Binomial[j, n-i-j], {j, 0, n-i}], {i, 0, n}], {n, 0, 22}]
PROG
(Maxima) makelist(sum(binomial(n+i, n)*sum(binomial(i+j-1, j)*binomial(j, n-i-j), j, 0, n-i), i, 0, n), n, 0, 22);
(PARI) for(n=0, 30, print1(sum(k=0, n, binomial(n+k, n)*sum(j=0, n-k, binomial(k+j-1, j)*binomial(j, n-k-j))), ", ")) \\ G. C. Greubel, Mar 04 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Emanuele Munarini, May 10 2011
STATUS
approved