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a(1) = 0; for n > 1, a(n) = k if n is a non-perfect-power, A007916(k); or 0 if n is a perfect power.
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%I #20 Feb 28 2024 05:20:17

%S 0,1,2,0,3,4,5,0,0,6,7,8,9,10,11,0,12,13,14,15,16,17,18,19,0,20,0,21,

%T 22,23,24,0,25,26,27,0,28,29,30,31,32,33,34,35,36,37,38,39,0,40,41,42,

%U 43,44,45,46,47,48,49,50,51,52,53,0,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,0

%N a(1) = 0; for n > 1, a(n) = k if n is a non-perfect-power, A007916(k); or 0 if n is a perfect power.

%H Rémy Sigrist, <a href="/A278029/b278029.txt">Table of n, a(n) for n = 1..10000</a>

%H N. J. A. Sloane, <a href="/A278028/a278028.txt">Maple programs for A007916, A278028, A278029, A052409, A089723, A277564</a>

%t FoldList[Boole[#2 != #1] #2 &, #] &@ Accumulate@ Array[Boole[And[# > 1, CoprimeQ @@ FactorInteger[#][[All, -1]]]] &, 81] (* _Michael De Vlieger_, Dec 18 2016 *)

%Y Cf. A007916, A072813, A289023.

%K nonn,easy

%O 1,3

%A _N. J. A. Sloane_, Nov 10 2016

%E Name corrected by _Peter Munn_, Feb 28 2024