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 A113031 #10 Dec 05 2013 19:57:06 %S A113031 1,2,3,3,7,29,4,9,289,332929,5,11,23,47,283,6,55,111,334,335,671,7,29, %T A113031 59,709,2837,22697,590123,8,4913,2084349468684419, %U A113031 24848244676397648518313556708104734780186593641363 %N A113031 Triangle read by rows: n-th row begins with n and contains n terms with the same prime signature such that the (r+1)-th term == 1 (mod r-th term). %e A113031 Triangle begins: %e A113031 1 %e A113031 2 3 %e A113031 3 7 29 %e A113031 4 9 289 332929... %K A113031 nonn,tabl %O A113031 1,2 %A A113031 _Amarnath Murthy_, Jan 04 2006 %E A113031 Corrected and extended by _Joshua Zucker_, May 07 2006 %E A113031 a(32) from _Max Alekseyev_, Feb 13 2012