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A160473 The p(n) sequence that is associated with the Eta triangle A160464. 6
3, 30, 315, 11340, 311850, 12162150, 638512875, 86837751000, 7424627710500, 779585909602500, 98617617564716250, 14792642634707437500, 2596108782391155281250, 527010082825404522093750, 122529844256906551386796875, 64695757767646659132228750000 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Table of n, a(n) for n=2..17.

FORMULA

a(n) = 2^(-(2*(n-1)-1-floor(log(n-1)/log(2))))*(2*n-1)! for n = 2, 3, 4, ... .

PROG

(PARI) vector(20, n, n++; 2^(-(2*(n-1)-1-floor(log(n-1)/log(2))))*(2*n-1)!) \\ Michel Marcus, Jul 06 2015

(MAGMA) [2^(-(2*(n-1)-1-Floor(Log(n-1)/Log(2))))*Factorial(2*n-1)  : n in [2..30]]; // Vincenzo Librandi, Jul 06 2015

CROSSREFS

A160464 is the Eta triangle.

Equals 3*(n-2)!*A000457(n-2)/A054243(n-1)

Equals 2^(-A049039(n-1))*(2*n-1)!

Cf. The pg(n) sequence A162440. - Johannes W. Meijer, Jul 06 2009

Sequence in context: A131586 A163475 A200142 * A144283 A229299 A178016

Adjacent sequences:  A160470 A160471 A160472 * A160474 A160475 A160476

KEYWORD

easy,nonn

AUTHOR

Johannes W. Meijer, May 24 2009

STATUS

approved

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Last modified November 19 02:38 EST 2018. Contains 317332 sequences. (Running on oeis4.)