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 A064689 #6 May 10 2013 12:44:53 %S A064689 0,1,2,3,6,7,12,15,32,43,48,61,136,159,240,527,572,1009,1022,1085, %T A064689 1910,2365,3782,6377,13384,17929,18736,25521,57840,155021,258058, %U A064689 266247,267278,278751,315806,328269 %N A064689 Smallest m such that A064672(m) = n. %C A064689 A064672(a(n)) = n and A064672(m) < n for m < a(n). %o A064689 (Haskell) %o A064689 import Data.List (elemIndex) %o A064689 import Data.Maybe (fromJust) %o A064689 a064689 = fromJust . (`elemIndex` a064672_list) %o A064689 -- _Reinhard Zumkeller_, Apr 27 2012 %Y A064689 Cf. A064672. %K A064689 nonn,easy %O A064689 0,3 %A A064689 Jonathan Ayres (jonathan.ayres(AT)btinternet.com), Oct 09 2001 %E A064689 More terms from _Vladeta Jovovic_, Oct 13 2001 %E A064689 Initial term added and offset adjusted by _Reinhard Zumkeller_, Apr 27 2012