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A198864 a(0) = 1; a(n) = n + product_{i=0..n-1} a(i), n >= 1. 1

%I #8 Mar 31 2012 10:24:05

%S 1,2,4,11,92,8101,65585702,4301483913318599,

%T 18502763856538658405109886092616,

%U 342352270330833327273885765082712290623512199361069533040982537

%N a(0) = 1; a(n) = n + product_{i=0..n-1} a(i), n >= 1.

%C The product of an empty set is 1, so a(0) = 1.

%C 5 - (1+1/2+1/4+1/11+1/92) = 3.14822... is close to Pi.

%H Arkadiusz Wesolowski, <a href="/A198864/b198864.txt">Table of n, a(n) for n = 0..14</a>

%F a(n) = n + a(0)*a(1)*...*a(n-1).

%t lst = {}; k = m = 1; Do[k = k*m; AppendTo[lst, k + n]; m = k + n, {n, 0, 9}]; lst

%K nonn

%O 0,2

%A _Arkadiusz Wesolowski_, Oct 30 2011

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)