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 A114478 #21 Feb 03 2023 04:53:56 %S A114478 0,1,4,2,6,8,3,9,10,12,4,14,15,16,18,5,20,21,22,24,25,6,26,27,28,30, %T A114478 32,33,7,34,35,36,38,39,40,42,8,44,45,46,48,49,50,51,52,9,54,55,56,57, %U A114478 58,60,62,63,64,10,65,66,68,69,70,72,74,75,76,77 %N A114478 Triangle read by rows; n-th row begins with n and contains n nonprimes greater than n and not already used. %e A114478 Triangle begins: %e A114478 0; %e A114478 1, 4; %e A114478 2, 6, 8; %e A114478 3, 9, 10, 12; %e A114478 4, 14, 15, 16, 18; %e A114478 5, 20, 21, 22, 24, 25; %Y A114478 Cf. A113167. %K A114478 nonn,tabl %O A114478 0,3 %A A114478 _Parthasarathy Nambi_, Feb 16 2006 %E A114478 More terms from _Sean A. Irvine_, Sep 22 2011 %E A114478 a(0)=0 inserted by _Michel Marcus_, Feb 03 2023