A266486 E.g.f.: Limit_{N->oo} [ Sum_{n>=0} (N + 3*n)^(2*n) * (x/N)^n/n! ]^(1/N).

1, 1, 13, 415, 22321, 1721101, 174252997, 21935478979, 3308902366945, 582483654850105, 117302814498577501, 26610247617703733479, 6716634535536518884177, 1867456548257171896034245, 567177496490226897535216405, 186852683125922747089699211851, 66371163246016212237620717414593, 25287323016605747194753141853886961, 10287301449354981886046538248627595565, 4450859089975905722184296672608494825775, 2040775907870521098252331495354110194770801

Offset

0,3

Comments

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!.

Links

Table of n, a(n) for n=0..20.

Example

E.g.f.: A(x) = 1 + x + 13*x^2/2! + 415*x^3/3! + 22321*x^4/4! + 1721101*x^5/5! + 174252997*x^6/6! + 21935478979*x^7/7! + 3308902366945*x^8/8! + 582483654850105*x^9/9! + 117302814498577501*x^10/10! +...
where A(x) equals the limit, as N -> oo, of the series
[1 + (N+3)^2*(x/N) + (N+6)^4*(x/N)^2/2! + (N+9)^6*(x/N)^3/3! + (N+12)^8*(x/N)^4/4! + (N+15)^10*(x/N)^5/5! + (N+18)^12*(x/N)^6/6! +...]^(1/N).

Prog

(PARI) /* Informal listing of terms 0..30 */
\p300
P(n) = sum(k=0, 32, (n+3*k)^(2*k) * x^k/k! +O(x^32))
Vec( round( serlaplace( subst(P(10^100)^(1/10^100), x, x/10^100) )*1.) )

Crossrefs

Cf. A266481, A266482, A266483, A266484, A266485, A266487.

Sequence in context: A088919 A201537 A258178 * A142484 A087872 A308341

Adjacent sequences: A266483 A266484 A266485 * A266487 A266488 A266489

Keyword

nonn

Author

Paul D. Hanna, Dec 30 2015

Status

approved