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A203427 a(n) = w(n+1)/(4*w(n)), where w = A203426. 3
-3, 48, -1000, 25920, -806736, 29360128, -1224440064, 57600000000, -3018173044480, 174359297654784, -11011033460963328, 754709361539940352, -55801305000000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..13.

FORMULA

a(n) = (1/4) * (n+1) * (-2(n+2))^n. - Andrei Asinowski, Nov 03 2015

MATHEMATICA

f[j_] := 1/(2 j + 2); z = 12;

v[n_] := Product[Product[f[k] - f[j], {j, 1, k - 1}], {k, 2, n}];

1/Table[v[n], {n, 1, z}]                 (* A203426 *)

Table[v[n]/(4 v[n + 1]), {n, 1, z - 1}]  (* A203427 *)

CROSSREFS

Cf. A203426, A203425.

Sequence in context: A270005 A218382 A195635 * A320668 A319732 A199012

Adjacent sequences:  A203424 A203425 A203426 * A203428 A203429 A203430

KEYWORD

sign

AUTHOR

Clark Kimberling, Jan 02 2012

EXTENSIONS

Name corrected by Andrei Asinowski, Nov 03 2015

STATUS

approved

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Last modified November 12 22:10 EST 2019. Contains 329079 sequences. (Running on oeis4.)