OFFSET
1,2
REFERENCES
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 828.
LINKS
Seiichi Manyama, Table of n, a(n) for n = 1..922
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
FORMULA
From Peter Bala, Jul 21 2024: (Start)
a(n) = Sum_{k = 0..n-1} binomial(4*n+k, k).
a(n) = 5*(5*n - 1)*(5*n - 2)*(5*n - 3)*(5*n - 4)/((4*n - 4)*(4*n - 2)*(4*n - 1)*(4*n + 1)) * a(n-1) with a(1) = 1. (End)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved