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 A128148 #15 Mar 31 2012 14:12:21 %S A128148 2,2929,41459,2352527,144937,1055,1829903,7316185805,114491, %T A128148 3146746271,5028467,20299,69609309001,129433,15307006153,2149705, %U A128148 66469,559182815,18429503,4529951,7094711,83591212702535,1251548749,38088889 %N A128148 a(n) = least k such that 3^k mod k = 2^n. %F A128148 a(n) = A078457(2^n). %e A128148 a(1) = A128149(3) = 2929. %e A128148 a(2) = A128150(3) = 41459. %Y A128148 Cf. A078457 = least k such that the remainder when 3^k is divided by k is n. %Y A128148 Cf. A036236, A128149, A128150. %K A128148 hard,nonn %O A128148 0,1 %A A128148 _Alexander Adamchuk_, Feb 16 2007 %E A128148 a(7)-a(9) from A078457. _Max Alekseyev_, Mar 11 2009 %E A128148 Extended by _Max Alekseyev_, Mar 15 2009 %E A128148 a(20) from _Hagen von Eitzen_, Aug 01 2009 %E A128148 a(21)-a(23) from _Max Alekseyev_, Feb 13 2012