OFFSET
0,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..500
Necdet Batir and Anthony Sofo, On some series involving reciprocals of binomial coefficients, Appl. Math. Comp., Vol. 220 (2013), pp. 331-338.
FORMULA
a(n) = n * A005810(n).
a(n) = A374522(n) + n.
a(n) == 0 (mod 4).
Sum_{n>=1} 1/a(n) = A225847.
Sum_{n>=1} (-1)^n/a(n) = A229703.
a(n) ~ 2^(8*n+1/2) * sqrt(n) / (3^(3*n+1/2) * sqrt(Pi)). - Amiram Eldar, Sep 23 2025
MATHEMATICA
a[n_] := n * Binomial[4*n, n]; Array[a, 25, 0]
PROG
(PARI) a(n) = n * binomial(4*n, n);
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Amiram Eldar, Dec 07 2024
STATUS
approved
