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 A261413 #7 Aug 27 2015 18:40:01 %S A261413 1,3,7,15,23,31,47,63,87,95,119,127,175,191,239,255,279,287,303,311, %T A261413 319,343,351,375,383,407,415,431,447,463,471,479,503,511,559,567,575, %U A261413 599,607,623,631,639,687,703,751,759,767,815,823,831,847,855,863,895,911,919,927,943,959,1007,1015,1023 %N A261413 Records in A109732. %H A261413 Alois P. Heinz, <a href="/A261413/b261413.txt">Table of n, a(n) for n = 1..20000</a> %Y A261413 Cf. A109732, A261412. %K A261413 nonn %O A261413 1,2 %A A261413 _N. J. A. Sloane_, Aug 25 2015