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 A143711 #4 Mar 30 2012 18:52:27 %S A143711 6,20,42,18,20,44,78,105,136,12,76,105,506,18,20,117,28,174,310,165, %T A143711 170,28,222,114,78,410,903,44,30,2162,24,28,30,68,1378,45,66,399,3422, %U A143711 12,610,186,84,130,2211,68,138,2485,18,292,555,8,1463,78,632,60,6806,12 %N A143711 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (1*2*3, 2*2*5, 2*3*7, 2*3*3, 2*2*5, 11*2*2, 3*13*2, 7*3*5,..). %e A143711 a(8)=7*3*5=105. %e A143711 a(9)=2*4*17=136. %e A143711 a(10)=2*3*2=12. %e A143711 a(11)=19*2*2=76. %e A143711 a(12)=5*3*7=105. %e A143711 a(13)=2*11*23=506, %e A143711 etc. %Y A143711 Cf. A141287, A141261, A136735. %K A143711 nonn %O A143711 1,1 %A A143711 _Juri-Stepan Gerasimov_, Nov 13 2008 %E A143711 a(43) corrected by _R. J. Mathar_, Apr 14 2010