A275611 a(0) = 1, a(n) = n * a(n-1)^2 + a(n-1).

1, 2, 10, 310, 384710, 740009305210, 3285682630785061608169810, 75569972451698504356522006689642008796426176222510, 45686565890803766858880247710072390769807010129716258796255559717444312778982342222557219570421823310

Offset

0,2

Links

Table of n, a(n) for n=0..8.

Formula

a(n) ~ c^(2^n) / n, where c = 2.49513423157979814033214501746049499374370018515926861932281537537499551261588753466... - Vaclav Kotesovec, Jan 28 2019

Mathematica

a[n_] := a[n - 1] (n*a[n - 1] + 1); a[0] = 1; Array[a, 9, 0] (* Robert G. Wilson v, Dec 24 2016 *)

Prog

(PARI) a(n) = if(n==0, 1, n * a(n-1)^2 + a(n-1));

Crossrefs

Cf. A052129.

Sequence in context: A111837 A092123 A079278 * A015178 A296178 A206152

Adjacent sequences: A275608 A275609 A275610 * A275612 A275613 A275614

Keyword

nonn,easy

Author

Daniel Suteu, Dec 24 2016

Status

approved