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 A133031 #8 Jul 29 2024 13:29:39 %S A133031 1,2,3,6,1,2,4,7,14,28,1,2,4,8,16,31,62,124,248,496,1,2,4,8,16,32,64, %T A133031 127,254,508,1016,2032,4064,8128,1,2,4,8,16,32,64,128,256,512,1024, %U A133031 2048,4096,8191,16382,32764,65528,131056,262112,524224,1048448,2096896 %N A133031 Triangle read by rows: row n lists divisors of n-th perfect number A000396(n). %H A133031 Harvey P. Dale, <a href="/A133031/b133031.txt">Table of n, a(n) for n = 1..5000</a> %H A133031 Omar E. Pol, <a href="http://www.polrpimos.com">Determinacion geometrica de los numeros primos y perfectos</a>. %t A133031 Divisors[PerfectNumber[Range[5]]]//Flatten (* _Harvey P. Dale_, Jul 29 2024 *) %Y A133031 Cf. A018254, A018487, A027750. Perfect numbers: A000396. %K A133031 nonn,tabf %O A133031 1,2 %A A133031 _Omar E. Pol_, Oct 26 2007