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 A257646 #7 Nov 19 2015 16:39:30 %S A257646 0,2,3,4,4,5,5,9,5,11,6,13,6,7,16,6,18,7,20,7,22,23,24,7,26,27,9,29,7, %T A257646 8,32,33,34,8,10,37,38,8,40,41,42,43,44,8,46,47,48,49,9,51,52,53,8,12, %U A257646 56,57,58,59,9,61,62,63,64,9,13,67,68,69,70,71,72 %N A257646 Index of first row of triangle A103284 containing n. %C A257646 a(n) <= n + 1. %H A257646 Reinhard Zumkeller, <a href="/A257646/b257646.txt">Table of n, a(n) for n = 1..1000</a> %o A257646 (Haskell) %o A257646 import Data.List (findIndex); import Data.Maybe (fromJust) %o A257646 a257646 n = fromJust $ findIndex (elem n) a103284_tabl %Y A257646 Cf. A103284, A058084. %K A257646 nonn %O A257646 1,2 %A A257646 _Reinhard Zumkeller_, Nov 19 2015