login
Denominator of the coefficient of z^(-2*n) in the Stirling-like asymptotic expansion of Product_{z=1..n} z^(z^3).
3

%I #22 Sep 05 2018 10:58:30

%S 1,5040,50803200,8449588224000,442893616349184000,

%T 55804595659997184000000,315568291905804875857920000000,

%U 211531737430299124385080934400000000,6522145617145034649275530739712000000000,254485460571619683408716971558739902464000000000

%N Denominator of the coefficient of z^(-2*n) in the Stirling-like asymptotic expansion of Product_{z=1..n} z^(z^3).

%C 1^(1^3)*2^(2^3)*...*n^(n^3) ~ A_3*n^(n^4/4+n^3/2+n^2/4-1/120)*exp(-n^4/16+n^/12)*(Sum_{k>=0} b(k)/n^k)^n, where A_3 is the third Bendersky constant.

%C a(n) is the denominator of b(n).

%H Seiichi Manyama, <a href="/A318714/b318714.txt">Table of n, a(n) for n = 0..134</a>

%H Weiping Wang, <a href="https://www.researchgate.net/publication/318153972_Some_asymptotic_expansions_on_hyperfactorial_functions_and_generalized_Glaisher-Kinkelin_constants">Some asymptotic expansions on hyperfactorial functions and generalized Glaisher-Kinkelin constants</a>, ResearchGate, 2017.

%F Let B_n be the Bernoulli number, and define the sequence {c_n} by the recurrence

%F c_0 = 1, c_n = (-3/n) * Sum_{k=0..n-1} B_{2*n-2*k+4}*c_k/((2*n-2*k+1)*(2*n-2*k+2)*(2*n-2*k+3)*(2*n-2*k+4)) for n > 0.

%F a(n) is the denominator of c_n.

%e 1^(1^3)*2^(2^3)*...*n^(n^3) ~ A_3*n^(n^4/4+n^3/2+n^2/4-1/120)*exp(-n^4/16+n^/12)*(1 - 1/(5040*n^2) + 1513/(50803200*n^4) - 127057907/(8449588224000*n^6) + 7078687551763/(442893616349184000*n^8) - 1626209947417109183/(55804595659997184000000*n^10) + ... ).

%Y Product_{z=1..n} z^(z^m): A001163/A001164 (m=0), A143475/A143476 (m=1), A317747/A317796 (m=2), A318713/A318714 (m=3).

%Y Cf. A243263 (A_3).

%K nonn,frac

%O 0,2

%A _Seiichi Manyama_, Sep 01 2018