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 A031942 #10 Jul 23 2013 23:45:50
%S A031942 1,2,3,4,6,7,8,9,11,12,13,14,17,18,19,24,25,27,28,29,30,33,34,35,36,
%T A031942 38,39,44,45,46,49,50,51,52,54,55,56,57,59,68,70,71,72,73,75,76,77,78,
%U A031942 97,98,99,100,102,103,108,109,110,113,114,115
%N A031942 Numbers with no consecutive equal base 4 digits.
%F A031942 A031942 = { n | A043278(n)=1 } = A043090 \ {0}. - M. F. Hasler, Jul 23 2013
%Y A031942 Cf. A000975 (base-2 analog), A031941 or A043089 (base-3 analog), A031943 or A043091 (base-5 analog), A043092, ..., A043096 (base-6 through base-10 analog).
%K A031942 nonn,base
%O A031942 1,2
%A A031942 _Clark Kimberling_
%E A031942 Edited by _Charles R Greathouse IV_, Aug 02 2010