# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a074592 Showing 1-1 of 1 %I A074592 #9 Oct 10 2024 08:17:30 %S A074592 2,2,2,2,3,2,2,3,2,2,2,2,2,3,2,5,2,2,3,2,2,2,3,2,2,2,3,2,2,5,2,3,2,2, %T A074592 2,3,5,2,2,3,2,2,2,3,2,7,2,2,2,2,5,2,3,2,2,7,2,3,2,5,2,2,3,2,2,2,3,2, %U A074592 2,2,3,2,2,5,2,3,2,7,2,2,3,2,2,3,2,2,7,2,3,2,2,2,3,2,11,2,5,2,3,2,2,2,3,2 %N A074592 Smallest prime factors of numbers that are not prime powers. %H A074592 Amiram Eldar, Table of n, a(n) for n = 1..10000 %F A074592 a(n) = A020639(A024619(n)). %F A074592 a(n) > 2 iff n+1 and n+2 are prime powers (A006549). %t A074592 s[n_] := Module[{f = FactorInteger[n]}, If[Length[f] > 1, f[[1, 1]], Nothing]]; Array[s, 200] (* _Amiram Eldar_, Oct 10 2024 *) %Y A074592 Cf. A006549, A020639, A024619, A074593, A074594, A074595. %K A074592 nonn %O A074592 1,1 %A A074592 _Reinhard Zumkeller_, Aug 25 2002 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE