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A020113 a(n) = ceiling of Gamma(n + 2/9)/Gamma(2/9). 2
1, 1, 1, 1, 2, 9, 43, 267, 1928, 15845, 146123, 1493701, 16762640, 204876709, 2708925369, 38526938569, 586465620431, 9513775620310, 163848357905336, 2985681188497228, 57391427290002262, 1160582196308934616, 24630133277222945727, 547336295049398793928 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,5

LINKS

Table of n, a(n) for n=0..23.

FORMULA

a(n) ~ sqrt(2*Pi)*n^(n-5/18)*exp(-n)/Gamma(2/9) as n -> infinity. - Robert Israel, Jun 07 2015

EXAMPLE

Gamma(6 + 2/9) = 176.09917208972649...

Gamma(2/9) = 4.1065795667...

176.09917208972649.../4.1065795667... = 42.8822... hence a(6) = 43.

MAPLE

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

MATHEMATICA

Table[Ceiling[Gamma[n + 2/9]/Gamma[2/9]], {n, 0, 19}] (* Alonso del Arte, Jun 07 2015 *)

PROG

(MAGMA) [Ceiling(Gamma(n + 2/9)/Gamma(2/9)): n in [0..30]]; // Vincenzo Librandi, Jun 08 2015

CROSSREFS

Sequence in context: A334680 A324619 A292099 * A272199 A260074 A294270

Adjacent sequences:  A020110 A020111 A020112 * A020114 A020115 A020116

KEYWORD

nonn

AUTHOR

Simon Plouffe

STATUS

approved

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Last modified May 16 09:28 EDT 2021. Contains 343940 sequences. (Running on oeis4.)