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 A072039 #14 May 26 2024 16:07:25 %S A072039 1,2,2,3,5,3,4,6,3,7,4,5,6,8,9,11,4,7,10,12,13,14,5,8,6,4,15,17,9,16, %T A072039 7,19,18,10,11,12,21,20,22,5,13,8,14,23,24,26,27,6,15,35,25,30,9,28, %U A072039 29,7,16,17,31,33,18,32,10,34,19,5,36,40,11,20,12,37,8,39,21,22,13,38,45,43 %N A072039 Row of Zorach additive triangle in which n appears (or 0 in the unlikely event that it does not). %H A072039 Reinhard Zumkeller, <a href="/A072039/b072039.txt">Table of n, a(n) for n = 1..1000</a> %H A072039 A. C. Zorach, <a href="http://www.cazort.net/static/triangle.php">Additive triangle</a> %H A072039 <a href="/A035312/a035312_2.hs.txt">Haskell programs for sequences in connection with Zorach additive triangle</a> %F A072039 If a(n) > 0: n = A035312(a(n)-1, A072038(n)-1). %e A072039 a(8)=6 since 8 appears in the sixth row. %o A072039 (Haskell) -- See link. %Y A072039 Cf. A035312, A035311, A035313, A035358, A072038. %K A072039 nonn %O A072039 1,2 %A A072039 _Henry Bottomley_, Jun 07 2002