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 A131886 #7 Feb 20 2019 05:34:22 %S A131886 1,2,4,8,6,16,32,12,64,128,24,30,256,36,512,48,1024,2048,96,72,60, %T A131886 4096,8192,192,16384,144,32768,384,120,216,210,65536,131072,768,288, %U A131886 180,262144,524288,1536,240,432,1048576,576,2097152,3072,4194304,8388608 %N A131886 Rearrange the rows of array A077569 by sorting the values on each row by noting the odd part of each signature and sorting as in A131822. %C A131886 The shape sequence for both arrays is A001055. %e A131886 A077569 begins %e A131886 1 %e A131886 2 %e A131886 4 %e A131886 6, 8 %e A131886 ... %e A131886 so this triangle begins %e A131886 1 %e A131886 2 %e A131886 4 %e A131886 8, 6 %e A131886 16 %e A131886 32, 12 %e A131886 64 %e A131886 128, 24, 30 %e A131886 ... %Y A131886 Cf. A001055, A025487, A077569, A131822, A122819, A131801. %K A131886 nonn,tabf,more %O A131886 1,2 %A A131886 _Alford Arnold_, Aug 15 2007