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 A102830 #8 May 26 2017 16:42:08 %S A102830 1,2,3,5,6,7,10,11,15,21,22,23,26,27,31,38,39,43,47,55,62,66,70,71,74, %T A102830 75,79,86,87,90,91,95,102,103,107,111,119,126,130,135,139,143,151,155, %U A102830 159,167,171,175,183,191,203,210,214,218,223,226,234,237,241,245,250 %N A102830 "True already", base 4, start 1: a(n) is the least integer such that the sequence up to a(n-1) written in base 4 contains floor(a(n)/4) copies of the digit a(n) % 4, with a(0) = 1. %D A102830 Inspired by discussion of "True so far" from _Eric Angelini_ (A102357). %Y A102830 Cf. A102823-A102829, A102357. %K A102830 nonn,easy,base %O A102830 0,2 %A A102830 _Hugo van der Sanden_, Feb 26 2005