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 A078340 #5 Dec 15 2017 17:36:08 %S A078340 2,6,3,9,6,1,8,18,9,4,1,5,11,11,7,21,3,1,13,3,7,9,12,3,5,54,11,1,14, %T A078340 11,15,2,34,5,12,48,3,7,3,25,3,7,13,7,10,2,6,15,28,4,7,36,7,3,36,3,56, %U A078340 16,2,2,3,6,15,12,4,7,3,3,3,11,24,3,33,9,10,11,2,49,13,162,13,44,7,24,1 %N A078340 Least k such that A078142(n) = A078142(n+k). %Y A078340 Cf. A078142. %K A078340 nonn %O A078340 2,1 %A A078340 _Jason Earls_, Nov 22 2002