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 A133928 #9 Jul 14 2024 18:31:58 %S A133928 1,2,5,11,17,31,47,83,109,127,149,211,277,307,353,499,653,709,823, %T A133928 1063,1153,1289,1319,1499,1613,1873,2417,2647,2897,3001,3407,3659, %U A133928 4201,5441,5843,6469,6691,6991,7559,8147,8669,9293,10267,10613,12007,12899,14321 %N A133928 Associate each least prime signature value with the corresponding prime number. %F A133928 a(n) = A000040[A025487(n-1)-1], n>1. - _R. J. Mathar_, Oct 09 2007 %e A133928 Let a(1) = 1 then note %e A133928 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 ... A000027 %e A133928 1 2 3 4 4 6 5 8 9 8 6 12 7 6 12 16 8 ... A064553 %e A133928 a(n) is formed by choosing the least prime signatures in row two which map to primes in row one yielding 1 2 5 11 17 ... since A025487 = 1 2 4 6 8 ... %Y A133928 Cf. A000040, A025487, A064553, A064555. %K A133928 easy,nonn %O A133928 1,2 %A A133928 _Alford Arnold_, Sep 29 2007 %E A133928 More terms from _R. J. Mathar_, Oct 09 2007