cp's OEIS Frontend

A055462 Superduperfactorials: product of first n superfactorials.

%I A055462 #70 Mar 19 2025 10:23:10
%S A055462 1,1,2,24,6912,238878720,5944066965504000,745453331864786829312000000,
%T A055462 3769447945987085350501386572267520000000000,
%U A055462 6916686207999802072984424331678589933649915805696000000000000000
%N A055462 Superduperfactorials: product of first n superfactorials.
%C A055462 Next term has 92 digits and is too large to display.
%C A055462 Starting with offset 1, a(n) is a 'Matryoshka doll' sequence with alpha=1, the multiplicative counterpart to the additive A000332. The sequence for m with alpha<=m<=L is then computed as Prod_{n=alpha..m}(Prod_{k=alpha..n}(Prod_{i=alpha..k}(i))). - _Peter Luschny_, Jul 14 2009
%H A055462 Miles Seventh, <a href="/A055462/b055462.txt">Table of n, a(n) for n = 0..20</a>
%H A055462 Shyam Sunder Gupta, <a href="https://doi.org/10.1007/978-981-97-2465-9_16">Fascinating Factorials</a>, Exploring the Beauty of Fascinating Numbers, Springer (2025) Ch. 16, 411-442.
%F A055462 a(n) = a(n-1)*A000178(n) = Product_{i=1..n} (i!)^(n-i+1) = Product_{i=1..n} i^((n-i+1)*(n-i+2)/2).
%F A055462 log a(n) = (1/6) n^3 log n - (11/36) n^3 + O(n^2 log n). - _Charles R Greathouse IV_, Jan 13 2012
%F A055462 a(n) = exp((6 + 13 n + 9 n^2 + 2 n^3 - 8*(n + 2)*log(A)-2*(n + 2)^2*log(2*Pi) + 4*(2 n + 1)*logG(n + 2) - 4*(n + 1)^2*logGamma(n + 2) + 8*psi(-3, n + 2))/8) where A is the Glaisher-Kinkelin constant, logG(z) is the logarithm of the Barnes G function (A000178), and psi(-3, z) is a polygamma function of negative order (i.e., the second iterated integral of logGamma(z)). - _Jan Mangaldan_, Mar 21 2013
%F A055462 a(n) ~ exp(Zeta(3)/(8*Pi^2) - (2*n+3)*(11*n^2 + 24*n - 3)/72) * n^((2*n+3)*(2*n^2 + 6*n + 3)/24) * (2*Pi)^((n+1)*(n+2)/4) / A^(n+3/2), where A = A074962 = 1.28242712910062263687... is the Glaisher-Kinkelin constant and Zeta(3) = A002117 = 1.2020569031595942853997... . - _Vaclav Kotesovec_, Feb 20 2015
%e A055462 a(4) = 1!2!3!4!*1!2!3!*1!2!*1! = 288*12*2*1 = 6912.
%p A055462 seq(mul(mul(mul(i, i=alpha..k), k=alpha..n), n=alpha..m), m=alpha..10); # _Peter Luschny_, Jul 14 2009
%t A055462 Table[Product[BarnesG[j], {j, k + 1}], {k, 10}] (* _Jan Mangaldan_, Mar 21 2013 *)
%t A055462 Table[Round[Exp[(n+2)*(n+3)*(2*n+5)/8] * Exp[PolyGamma[-3, n+3]] * BarnesG[n+3]^(n+3/2) / (Glaisher^(n+3) * (2*Pi)^((n+3)^2/4) * Gamma[n+3]^((n+2)^2/2))], {n, 0, 10}] (* _Vaclav Kotesovec_, Feb 20 2015 after _Jan Mangaldan_ *)
%t A055462 Nest[FoldList[Times,#]&,Range[0,15]!,2]  (* _Harvey P. Dale_, Jul 14 2023 *)
%o A055462 (PARI) a(n)=my(t=1);prod(k=2,n,t*=k!) \\ _Charles R Greathouse IV_, Jul 28 2011
%o A055462 (Magma) [n eq 0 select 1 else (&*[j^Binomial(n-j+2,2): j in [1..n]]): n in [0..10]]; // _G. C. Greubel_, Jan 31 2024
%o A055462 (SageMath) [product(j^binomial(n-j+2,2) for j in range(1,n+1)) for n in range(11)] # _G. C. Greubel_, Jan 31 2024
%Y A055462 Cf. A000142, A000178, A002109, A036740, A255268, A255269, A306635.
%Y A055462 Cf. A057527, A057528, A260404.
%K A055462 nonn,easy
%O A055462 0,3
%A A055462 _Henry Bottomley_, Jun 26 2000
%E A055462 a(9) from _N. J. A. Sloane_, Dec 15 2008