This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A080065 #6 Aug 15 2013 17:57:16 %S A080065 3,15,27,39,51,63,75,87,91,99,111,123,135,147,159,171,183,195,203,207, %T A080065 219,231,243,255,259,267,279,291,303,315,327,339,351,363,371,375,387, %U A080065 399,411,423,427,435,447,459,471,483,495,507,519,531,539,543,555,567 %N A080065 Numbers n such that n == 3 modulo (spf(n)+1), where spf(m) is the smallest prime dividing m (A020639). %C A080065 A080063(m) = 3 iff m = a(k) for some k. %H A080065 Harvey P. Dale, <a href="/A080065/b080065.txt">Table of n, a(n) for n = 1..1000</a> %t A080065 Select[Range[600],Mod[#,FactorInteger[#][[1,1]]+1]==3&] (* _Harvey P. Dale_, Aug 15 2013 *) %Y A080065 Cf. A080064. %K A080065 nonn %O A080065 1,1 %A A080065 _Reinhard Zumkeller_, Jan 24 2003