OFFSET
0,2
FORMULA
a(n) = Sum_{k=0..n} binomial(n-1,n-k) * binomial(4*k+2,k)/(k+1).
G.f.: A(x) = B(x/(1-x)), where B(x) = (1/x) * Series_Reversion( x*(1-x)^3 ).
G.f.: A(x) = B(x)^3 where B(x) is the g.f. of A349331.
PROG
(PARI) a(n) = sum(k=0, n, binomial(n-1, n-k)*binomial(4*k+2, k)/(k+1));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 25 2024
STATUS
approved