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 A264856 #4 Nov 26 2015 17:09:43 %S A264856 0,2,3,4,5,6,7,6,9,10,11,8,11,10,15,16,17,18,14,12,15,22,12,18,12,22, %T A264856 27,18,13,20,15,32,33,34,13,36,37,14,15,14,38,42,43,44,45,16,24,13,25, %U A264856 50,51,52,53,54,31,56,45,58,59,60,19,62,63,64,65,66,67 %N A264856 Index of first row of triangle A125605 containing n. %H A264856 Reinhard Zumkeller, <a href="/A264856/b264856.txt">Table of n, a(n) for n = 1..1000</a> %o A264856 (Haskell) %o A264856 import Data.List (findIndex); import Data.Maybe (fromJust) %o A264856 a264856 n = fromJust $ findIndex (elem n) a125605_tabl %Y A264856 Cf. A125605, A058084. %K A264856 nonn %O A264856 1,2 %A A264856 _Reinhard Zumkeller_, Nov 26 2015