A020068 a(n) = floor( Gamma(n+2/9) / Gamma(2/9) ).

1, 0, 0, 0, 1, 8, 42, 266, 1927, 15844, 146122, 1493700, 16762639, 204876708, 2708925368, 38526938568, 586465620430, 9513775620309, 163848357905335, 2985681188497227, 57391427290002261, 1160582196308934615

Offset

0,6

Links

G. C. Greubel, Table of n, a(n) for n = 0..445

Maple

Digits := 64:f := proc(n, x) trunc(GAMMA(n+x)/GAMMA(x)); end;
seq(floor(pochhammer(2/9, n)), n = 0..25); # G. C. Greubel, Nov 13 2019

Mathematica

Floor[Pochhammer[2/9, Range[0, 25]]] (* G. C. Greubel, Nov 13 2019 *)

Prog

(PARI) x=2/9; vector(26, n, gamma(n-1+x)\gamma(x) ) \\ G. C. Greubel, Nov 13 2019
(Magma) [Floor(Gamma(n+2/9)/Gamma(2/9)): n in [0..25]]; // G. C. Greubel, Nov 13 2019
(Sage) [floor(rising_factorial(2/9, n)) for n in (0..25)] # G. C. Greubel, Nov 13 2019

Crossrefs

Cf. A020064, A020065, A020066, A020067, A020069.

Cf. A020023, A020113.

Sequence in context: A047759 A047772 A204565 * A266474 A238723 A316283

Adjacent sequences: A020065 A020066 A020067 * A020069 A020070 A020071

Keyword

nonn

Author

Simon Plouffe

Status

approved