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 A203512 a(n) = A203511(n+1)/A203511(n). 2
 1, 4, 63, 2288, 151200, 15909696, 2447297356, 518678754048, 145022370451200, 51747613910720000, 22956761806169786496, 12397159038346976323584, 8008689946841913447559168, 6099405371286264105062400000, 5408896545253926024119820000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS G. C. Greubel, Table of n, a(n) for n = 0..220 FORMULA a(n) ~ 2 * n^(2*n) / exp((2 - Pi/2)*n - 3*Pi/4). - Vaclav Kotesovec, Sep 07 2023 MATHEMATICA f[j_] := j (j + 1)/2; z = 15; v[n_] := Product[Product[f[k] + f[j], {j, 1, k - 1}], {k, 2, n}] Table[v[n], {n, 1, z}] (* A203511 *) Table[v[n + 1]/v[n], {n, 1, z - 1}] (* A203512 *) Table[Product[(n+2)*(n+1)/2 + j*(j+1)/2, {j, 1, n}], {n, 0, 10}] (* Vaclav Kotesovec, Sep 07 2023 *) PROG (Magma) [1] cat [(&*[(n+1)*(n+2) +j*(j+1): j in [1..n]])/2^n: n in [1..30]]; // G. C. Greubel, Feb 23 2024 (SageMath) def A203512(n): return product((n+1)*(n+2)+j*(j+1) for j in range(1, n+1))//2^n [A203512(n) for n in range(31)] # G. C. Greubel, Feb 23 2024 CROSSREFS Cf. A000217, A093883, A203511. Sequence in context: A024256 A292394 A351779 * A354653 A213545 A362386 Adjacent sequences: A203509 A203510 A203511 * A203513 A203514 A203515 KEYWORD nonn AUTHOR Clark Kimberling, Jan 03 2012 EXTENSIONS More terms from Alois P. Heinz, Jul 29 2017 STATUS approved

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Last modified April 25 09:28 EDT 2024. Contains 371967 sequences. (Running on oeis4.)