OFFSET
0,4
REFERENCES
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 255.
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..450
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].
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 255.
FORMULA
a(n)=floor((2n-1)!!/2^n*sqrt(Pi)) where (2n-1)!!=prod(k=1, n, 2*k-1); asymptotically a(n)=n!/sqrt(n)*(1-1/(8n)+1/(128n^2)-5/(1024n^3)+O(1/n^4)) - Benoit Cloitre, Apr 29 2003
MAPLE
seq(floor(evalf(GAMMA(n+1/2), 100)), n=0..24);
MATHEMATICA
a[n_] := Floor[Gamma[n + 1/2]]; Array[a, 21, 0] (* Amiram Eldar, Sep 20 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved