OFFSET
1,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = A025179(n) + 2, n>2.
MATHEMATICA
Join[{1, 3}, Table[Sum[ Binomial[n, 2*k]*Binomial[2*k + 1, k + 1], {k, 0, Floor[n/2]}] + 2, {n, 2, 50}]] (* G. C. Greubel, May 22 2017 *)
PROG
(PARI) concat([1, 3], for(n=2, 50, print1(2 + sum(k=0, floor(n/2), binomial(n, 2*k)*binomial(2*k+1, k+1)), ", "))) \\ G. C. Greubel, May 22 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved