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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, 4427218577690292387840, -375183514207494575620096, 33824309717272203758665728, -3232463698006063164519284736, 326417514496000000000000000000
OFFSET
1,1
LINKS
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, k-1}], {k, 2, n}];
1/Table[v[n], {n, z}] (* A203426 *)
Table[v[n]/(4 v[n + 1]), {n, z}] (* 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
Sequence in context: A270005 A218382 A195635 * A365651 A320668 A319732
KEYWORD
sign
AUTHOR
Clark Kimberling, Jan 02 2012
EXTENSIONS
Name corrected by Andrei Asinowski, Nov 03 2015
Terms a(14) onward added by G. C. Greubel, Dec 05 2023
STATUS
approved