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A101504 a(n+1)=a(n)/x+x, with x = Max(a(k): 0<=k<n and a(k)|a(n)), a(0)=a(1)=1. 2

%I #6 Aug 24 2016 18:11:36

%S 1,1,2,3,4,4,5,6,5,6,7,8,6,7,8,9,6,7,8,9,10,7,8,9,10,11,12,8,9,10,11,

%T 12,13,14,9,10,11,12,13,14,15,8,9,10,11,12,13,14,15,16,10,11,12,13,14,

%U 15,16,17,18,11,12,13,14,15,16,17,18,19,20,12,13,14,15,16,17,18,19,20,21

%N a(n+1)=a(n)/x+x, with x = Max(a(k): 0<=k<n and a(k)|a(n)), a(0)=a(1)=1.

%C a(n)>a(n+1) iff a(n) is composite and a(n)>Max(a(k):0<=k<n);

%C a(A101505(n)) = n and a(m) < n for m < A101505(n).

%H Ivan Neretin, <a href="/A101504/b101504.txt">Table of n, a(n) for n = 0..10000</a>

%t Nest[Append[#, (x = Max@Intersection[Most@#, Divisors[#[[-1]]]]) + #[[-1]]/x] &, {1, 1}, 77] (* _Ivan Neretin_, Aug 24 2016 *)

%K nonn

%O 0,3

%A _Reinhard Zumkeller_, Dec 05 2004

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