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 A183232 #9 Mar 30 2012 18:57:12 %S A183232 2,8,5,53,12,26,9,1538,63,103,17,404,33,64,14,1186568,1593,2143,74, %T A183232 5563,117,188,23,82619,432,628,41,2209,75,134,20,703974775733,1188108, %U A183232 1272808,1649,2301583,2208,2924,86,15487393 %N A183232 Second of two complementary trees generated by the triangular numbers. The other tree is A183231. %C A183232 See A183231 (first tree). %F A183232 See the formulas at A183231 and A183244. %e A183232 First 3 levels: %e A183232 ....................2 %e A183232 ...............8...........5 %e A183232 ............53...12.....26...9 %Y A183232 Cf. A183079, A183231, A183244. %K A183232 nonn,tabf %O A183232 1,1 %A A183232 _Clark Kimberling_, Jan 02 2011