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 A056232 #8 Jul 13 2013 12:02:32 %S A056232 3,6,11,15,18,22,25,27,30,35,39,41,44,51,59,63,66,70,73,75,81,88,91, %T A056232 94,97,99,103,107,109,111,114,118,121,123,126,131,135,137,140,147,153, %U A056232 155,157,161,165,167,170,173,176,181,188,194,198,201,203 %N A056232 Form an array with 3 rows: row 1 begins with 1; all rows are increasing; each entry is sum of 2 entries above it; each number appears at most once; smallest unused number is appended to first row if possible. Sequence gives row 2. %H A056232 Reinhard Zumkeller, <a href="/A056232/b056232.txt">Table of n, a(n) for n = 1..10000</a> %e A056232 Array begins %e A056232 1 2 4 7 8 10 12 ... %e A056232 .3 6 11 15 18 ... %e A056232 . 9 17 26 33 ... %o A056232 (Haskell) cf. A056231. %Y A056232 Cf. A056231, A056233, A056234. See also A057153, A052474, A057154, A056230. %K A056232 nonn,nice,easy %O A056232 1,1 %A A056232 _N. J. A. Sloane_, E. M. Rains, Aug 22 2000