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 A057153 #15 Dec 06 2014 01:34:20 %S A057153 1,3,9,26,73,194,485,1150,2617,5779,12497,26653,56355,118545,248605, %T A057153 520365,1087853,2272770,4748677,9930475,20800122,43658310,91836751, %U A057153 193549010,408449129,862455193,1820771343,3840569196,8089327515 %N A057153 Construct difference array so that (1) first row begins with 1, (2) every row is monotonic increasing, (3) no number appears more than once, (4) smallest number not yet used begins a new row. Sequence gives first row of array. %C A057153 This is the limit of the family of sequences starting with A005228, A037257, A037260. Adjoin next free number as the first element in a new level of differences unless it would produce a duplicate in which case ignore. %H A057153 Reinhard Zumkeller, <a href="/A057153/b057153.txt">Table of n, a(n) for n = 1..150</a> %F A057153 Row sums of triangle A133544. - _Gary W. Adamson_, Sep 14 2007 %e A057153 Array begins %e A057153 1 3 9 26 73 194 ... %e A057153 .2 6 17 47 121 ... %e A057153 . 4 11 30 74 ... %e A057153 .. 7 19 44 ... %e A057153 ... 12 25 ... %e A057153 .... 13 ... %o A057153 (Haskell) %o A057153 a057153 n = a056230_tabl !! (n-1) !! (n-1) %o A057153 -- _Reinhard Zumkeller_, Nov 19 2011 %Y A057153 Cf. A057154 (numbers not used), A052474 (main diagonal), A056230 (array). See also A005228, A037257, A037260, A057267, A056231, A056232, A056233, A056234. %Y A057153 Cf. A133544. %Y A057153 Cf. A200379 (first differences). %K A057153 nice,nonn,easy %O A057153 1,2 %A A057153 _Jonas Wallgren_, Jul 30 2000 %E A057153 More terms from Rob Speer (rob(AT)twcny.rr.com) and Loren Merritt, Aug 14 2000