A004168 - OEIS

A004168

a(n+1) = a(n)*(a(n)+1).

3, 12, 156, 24492, 599882556, 359859081592975692, 129498558604939936868397356895854556, 16769876680757063368089314196389622249367851612542961252860614401811692

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OFFSET

0,1

COMMENTS

The next term (a(8)) has 141 digits. - Harvey P. Dale, Jul 02 2021

LINKS

Table of n, a(n) for n=0..7.

FORMULA

a(n) = A082732(n+3) - 1. - Max Alekseyev, Aug 09 2019

MAPLE

A004168 := proc(n) option remember; if n=0 then 3 else A004168(n-1)*(A004168(n-1)+1); fi; end;

MATHEMATICA

a = {3}; Do[AppendTo[a, a[[n - 1]] (a[[n - 1]] + 1)], {n, 2, 8}]; a (* Michael De Vlieger, Feb 23 2016 *)

NestList[#(#+1)&, 3, 7] (* Harvey P. Dale, Jul 02 2021 *)

PROG

(Magma) [n eq 1 select 3 else Self(n-1)*(Self(n-1)+1): n in [1..10]]; // Vincenzo Librandi, Feb 23 2016

CROSSREFS

Cf. A000058, A007018.

Sequence in context: A098152 A028301 A356719 * A301650 A061960 A120606

Adjacent sequences: A004165 A004166 A004167 * A004169 A004170 A004171

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane

EXTENSIONS

a(7) from Vincenzo Librandi, Feb 23 2016

STATUS

approved