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 A193551 #15 Mar 30 2012 18:51:10 %S A193551 1,2,3,4,5,6,7,16,27,10,11,12,13,14,15,256,17,24,19,20,21,22,23,36, %T A193551 3125,26,19683,28,29,30,31,65536,33,34,35,72,37,38,39,80,41,42,43,44, %U A193551 135,46,47,144,823543,160,51,52,53,216,55,112,57,58,59,60,61,62 %N A193551 Smallest number with n as multiplicative projection. %C A193551 A000026(a(n)) = n and A000026(m) <> n for m < a(n); %C A193551 a(p^k) = p^(p^(k-1)), p prime, k > 0; the sequence is not multiplicative, but for coprime odd numbers u, v: a(u*v) = a(u) * a(v); %C A193551 A078779 gives fixed points: a(A078779(n)) = A078779(n). %o A193551 (Haskell) %o A193551 import Data.List (elemIndex, findIndices) %o A193551 import Data.Maybe (fromJust) %o A193551 a193551 n = (fromJust $ elemIndex n a000026_list) + 1 %K A193551 nonn %O A193551 1,2 %A A193551 _Reinhard Zumkeller_, Aug 27 2011