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 A278447 #24 Dec 11 2016 00:23:46 %S A278447 2,4,3,3,8,4,4,12,5,5,16,6,4,6,10,10,7,7,24,8,8,13,13,9,8,9,32 %N A278447 Irregular triangle read by rows in which row n lists the semiperimeters of the parts of the symmetric representation of sigma(n). %F A278447 a(n) = A279160(n)/2. %e A278447 Triangle begins: %e A278447 2; %e A278447 4; %e A278447 3, 3; %e A278447 8; %e A278447 4, 4; %e A278447 12; %e A278447 5, 5; %e A278447 16; %e A278447 6, 4, 6; %e A278447 10, 10; %e A278447 7, 7; %e A278447 24; %e A278447 8, 8; %e A278447 13, 13; %e A278447 9, 8, 9; %e A278447 32; %e A278447 ... %e A278447 For n = 9 the symmetric representation of sigma(9) = 13 has three parts of areas 5, 3, 5 respectively. The perímeters of the parts are 12, 8 and 12, so the 9th row of triangle lists the semiperimeters: 6, 4, 6. %Y A278447 Row sums give A244363. %Y A278447 Cf. A237271 gives the row lengths. %Y A278447 Cf. A000203, A196020, A236104, A235791, A237270, A237591, A237593, A245092, A262626, A279160. %K A278447 nonn,tabf,more %O A278447 1,1 %A A278447 _Omar E. Pol_, Dec 07 2016