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Revision History for A203427

(Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing entries 1-10 | older changes

A203427

a(n) = w(n+1)/(4*w(n)), where w = A203426.
(history; published version)

#24 by OEIS Server at Tue Dec 05 08:34:19 EST 2023

LINKS

G. C. Greubel, <a href="/A203427/b203427_1.txt">Table of n, a(n) for n = 1..345</a>

#23 by Joerg Arndt at Tue Dec 05 08:34:19 EST 2023

STATUS

reviewed

approved

Discussion

Tue Dec 05

08:34

OEIS Server: Installed first b-file as b203427.txt.

#22 by Michel Marcus at Tue Dec 05 04:28:57 EST 2023

STATUS

proposed

reviewed

#21 by G. C. Greubel at Tue Dec 05 04:02:34 EST 2023

STATUS

editing

proposed

Discussion

Tue Dec 05

04:28

Michel Marcus: ok

#20 by G. C. Greubel at Tue Dec 05 04:02:29 EST 2023

DATA

-3, 48, -1000, 25920, -806736, 29360128, -1224440064, 57600000000, -3018173044480, 174359297654784, -11011033460963328, 754709361539940352, -55801305000000000000, 4427218577690292387840, -375183514207494575620096, 33824309717272203758665728, -3232463698006063164519284736, 326417514496000000000000000000

EXTENSIONS

Terms a(14) onward added by G. C. Greubel, Dec 05 2023

STATUS

proposed

editing

#19 by G. C. Greubel at Tue Dec 05 02:34:03 EST 2023

STATUS

editing

proposed

Discussion

Tue Dec 05

02:52

Michel Marcus: please add more terms to data section

#18 by G. C. Greubel at Tue Dec 05 02:33:43 EST 2023

LINKS

G. C. Greubel, <a href="/A203427/b203427_1.txt">Table of n, a(n) for n = 1..345</a>

FORMULA

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

MATHEMATICA

(* First program *)

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 *)

(* Second program *)

Table[(-2*(n+2))^n*(n+1)/4, {n, 20}] (* G. C. Greubel, Dec 05 2023 *)

PROG

(Magma) [(-2*(n+2))^n*(n+1)/4: n in [1..20]]; // G. C. Greubel, Dec 05 2023

(SageMath) [(-2*(n+2))^n*(n+1)/4 for n in range(1, 21)] # G. C. Greubel, Dec 05 2023

CROSSREFS

Cf. A203426, A203425, A203426.

STATUS

approved

editing

#17 by Vaclav Kotesovec at Sat Dec 05 05:45:54 EST 2015

STATUS

editing

approved

#16 by Vaclav Kotesovec at Sat Dec 05 05:44:10 EST 2015

MATHEMATICA

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

STATUS

proposed

editing

#15 by Omar E. Pol at Wed Nov 04 06:32:29 EST 2015

STATUS

editing

proposed

Discussion

Fri Nov 06

09:26

Andrei Asinowski: Edited as suggested, and signed.