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A020040 a(n) = round( Gamma(n+1/5)/Gamma(1/5) ). 2

%I #13 Sep 08 2022 08:44:44

%S 1,0,0,1,2,7,37,229,1647,13507,124269,1267543,14196477,173197024,

%T 2286200718,32464050199,493453563029,7993947721071,137495900802424,

%U 2502425394604114,48046567576398986,970540665043259525

%N a(n) = round( Gamma(n+1/5)/Gamma(1/5) ).

%C Gamma(n+1/5)/Gamma(1/5) = 1, 1/5, 6/25, 66/125, 1056/625, 22176/3125, 576576/15625, 17873856/78125, ... - _R. J. Mathar_, Sep 04 2016

%H G. C. Greubel, <a href="/A020040/b020040.txt">Table of n, a(n) for n = 0..450</a>

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

%p seq( round(pochhammer(1/5, n)), n=0..30); # _G. C. Greubel_, Dec 06 2019

%t Table[Round[Pochhammer[1/5,n]], {n,0,30}] (* _G. C. Greubel_, Dec 06 2019 *)

%o (PARI) x=1/5; vector(30, n, round(gamma(n-1+x)/gamma(x)) ) \\ _G. C. Greubel_, Dec 06 2019

%o (Magma) [Round(Gamma(n+1/5)/Gamma(1/5)): n in [0..30]]; // _G. C. Greubel_, Dec 06 2019

%o (Sage) [round(rising_factorial(1/5,n)) for n in (0..30)] # _G. C. Greubel_, Dec 06 2019

%Y Cf. A008548, A020085, A020130.

%K nonn

%O 0,5

%A _Simon Plouffe_

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Last modified May 15 10:29 EDT 2024. Contains 372540 sequences. (Running on oeis4.)