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a(0)=1. a(n) = A020639(a(n-1)) + n.
1

%I #11 Nov 26 2020 16:51:08

%S 1,2,4,5,9,8,8,9,11,20,12,13,25,18,16,17,33,20,20,21,23,44,24,25,29,

%T 54,28,29,57,32,32,33,35,38,36,37,73,110,40,41,81,44,44,45,47,92,48,

%U 49,55,54,52,53,105,56,56,57,59,116,60,61,121,72,64,65,69,68,68,69,71,140,72

%N a(0)=1. a(n) = A020639(a(n-1)) + n.

%H Robert Israel, <a href="/A116920/b116920.txt">Table of n, a(n) for n = 0..10000</a>

%p lpf:= proc(n) min(numtheory:-factorset(n)) end proc: lpf(1):= 1:

%p A:= Array(0..100): A[0]:= 1:

%p for n from 1 to 100 do A[n]:= lpf(A[n-1])+n od:

%p convert(A,list); # _Robert Israel_, Nov 26 2020

%t a[0] := 1; a[1] := 2; a[n_] := FactorInteger[a[n - 1]][[1]][[1]] + n; Table[a[n], {n, 0, 80}] (* _Stefan Steinerberger_, Mar 27 2006 *)

%Y Cf. A020639, A116919.

%K nonn,look

%O 0,2

%A _Leroy Quet_, Feb 26 2006

%E More terms from _Stefan Steinerberger_, Mar 27 2006