A020135 Ceiling of Gamma(n+1/2)/Gamma(1/2).

1, 1, 1, 2, 7, 30, 163, 1056, 7919, 67304, 639384, 6713531, 77205602, 965070018, 13028445232, 188912455861, 2928143065835, 48314360586265, 845501310259628, 15641774239803108, 305014597676160594, 6252799252361292174

Offset

0,4

Comments

Gamma(n+1/2)/Gamma(1/2) = 1, 1/2, 3/4, 15/8, 105/16, 945/32, 10395/64, 135135/128, 2027025/256, ... - R. J. Mathar, Sep 04 2016

Links

G. C. Greubel, Table of n, a(n) for n = 0..449

Maple

Digits := 64:f := proc(n, x) ceil(GAMMA(n+x)/GAMMA(x)); end;

Mathematica

Table[Ceiling[Pochhammer[1/2, n]], {n, 0, 30}] (* G. C. Greubel, Nov 19 2018 *)

Prog

(PARI) default(realprecision, 100); for(n=0, 30, print1(ceil(gamma(n+1/2)/gamma(1/2)), ", ")) \\ G. C. Greubel, Nov 19 2018
(Magma) [Ceiling(Gamma(n + 1/2)/Gamma(1/2)): n in [0..30]]; // G. C. Greubel, Nov 19 2018
(Sage) [ceil(gamma(n+1/2)/gamma(1/2)) for n in range(30)] # G. C. Greubel, Nov 19 2018

Crossrefs

Cf. A020090, A020135.

Sequence in context: A001053 A124552 A020045 * A249474 A193353 A102158

Adjacent sequences: A020132 A020133 A020134 * A020136 A020137 A020138

Keyword

nonn

Author

Simon Plouffe

Status

approved