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E.g.f.: Limit_{N->oo} [ Sum_{n>=0} (N + n)^(5*n) * (x/N^4)^n/n! ]^(1/N).
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%I #15 Mar 20 2024 09:20:42

%S 1,1,11,316,15741,1140376,109350271,13100626176,1886686497401,

%T 317762099341696,61318533545522451,13343942849386863616,

%U 3233753469962945660341,863794149132594286734336,252178372791563562485494151,79890921514691257167186558976,27298165065421976828646695794161,10007689235634878438090676073824256,3918413783588692571816707646546345371,1631982989611299844119224469019967225856,720447625733586591482575137323090206302701

%N E.g.f.: Limit_{N->oo} [ Sum_{n>=0} (N + n)^(5*n) * (x/N^4)^n/n! ]^(1/N).

%C Compare to: Limit_{N->oo} [ Sum_{n>=0} (N + n)^n * x^n/n! ]^(1/N) = Sum_{n>=0} (n+1)^(n-1) * x^n/n!.

%H Vaclav Kotesovec, <a href="/A266484/b266484.txt">Table of n, a(n) for n = 0..100</a>

%F E.g.f. A(x) = Sum_{n>=0} a(n)*x^n/n! may be defined as follows.

%F (1) A(x) = Limit_{N->oo} [ Sum_{n>=0} (N + n)^(5*n) * (x/N^4)^n/n! ]^(1/N).

%F (2) A(x) = exp( Sum_{n>=0} L(n)*x^n/n! ), where L(n) = [x^n*y^(4*n+1)/n!] log( Sum_{n>=0} (n + y)^(5*n) * x^n/n! ). - _Paul D. Hanna_, Jan 29 2023

%F a(n) ~ 5^(5*n/2 + 1/4) * (1 + sqrt(5))^(3*n - 3/2) * exp((4-2*sqrt(5))*n - 4*sqrt(5) + 9) * n^(n-2) / 2^(7*n + 1). - _Vaclav Kotesovec_, Mar 20 2024

%e E.g.f.: A(x) = 1 + x + 11*x^2/2! + 316*x^3/3! + 15741*x^4/4! + 1140376*x^5/5! + 109350271*x^6/6! + 13100626176*x^7/7! + 1886686497401*x^8/8! + 317762099341696*x^9/9! + 61318533545522451*x^10/10! +...

%e where A(x) equals the limit, as N -> oo, of the series

%e [1 + (N+1)^5*(x/N^4) + (N+2)^10*(x/N^4)^2/2! + (N+3)^15*(x/N^4)^3/3! + (N+4)^20*(x/N^4)^4/4! + (N+5)^25*(x/N^4)^5/5! + (N+6)^30*(x/N^4)^6/6! +...]^(1/N).

%o (PARI) /* Informal listing of terms 0..30 */

%o \p500

%o P(n) = sum(k=0,32, (n+k)^(5*k) * x^k/k! +O(x^32))

%o Vec(round(serlaplace( subst(P(10^100)^(1/10^100),x,x/10^400) )*1.) )

%o (PARI) /* Using logarithmic formula */

%o {L(n) = n! * polcoeff( polcoeff( log( sum(m=0, n+1, (m + y)^(5*m) *x^m/m! ) +x*O(x^n) ), n, x), 4*n+1, y)}

%o {a(n) = n! * polcoeff( exp( sum(m=1, n+1, L(m)*x^m/m! ) +x*O(x^n)), n)}

%o for(n=0, 20, print1(a(n), ", ")) \\ _Paul D. Hanna_, Jan 29 2023

%Y Cf. A266481, A266482, A266483, A266485, A266486.

%K nonn

%O 0,3

%A _Paul D. Hanna_, Dec 30 2015