A014510 - OEIS

%I #19 Sep 20 2019 13:13:14

%S 1,0,1,3,11,52,287,1871,14034,119292,1133278,11899423,136843365,

%T 1710542068,23092317922,334838609873,5189998453040,85634974475162,

%U 1498612053315336,27724322986333718,540624298233507504

%N a(n) = floor( Gamma(n+1/2) ).

%D M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 255.

%H Amiram Eldar, <a href="/A014510/b014510.txt">Table of n, a(n) for n = 0..450</a>

%H M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].

%H M. Abramowitz and I. A. Stegun, eds., <a href="http://www.convertit.com/Go/ConvertIt/Reference/AMS55.ASP">Handbook of Mathematical Functions</a>, National Bureau of Standards Applied Math. Series 55, Tenth Printing, 1972, p. 255.

%F 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

%p seq(floor(evalf(GAMMA(n+1/2),100)), n=0..24);

%t a[n_] := Floor[Gamma[n + 1/2]]; Array[a, 21, 0] (* _Amiram Eldar_, Sep 20 2019 *)

%Y Cf. A014511, A014512, A014513, A014514, A014516, A014517, A014518, A014521, A014522.

%K nonn

%O 0,4

%A _Simon Plouffe_