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 A143704 #10 Nov 17 2019 01:28:22 %S A143704 9,20,35,15,20,26,32,50,102,10,42,56,299,15,14,48,28,93,72,88,95,18, %T A143704 185,63,45,92,430,44,25,1175,18,18,21,38,132,30,39,190,1829,12,132,68, %U A143704 54,36,938,68,52,852,15,150,200,8,286,65,324,32,3569,12,204,135,93,200,25,40 %N A143704 (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, ...). %H A143704 Robert Israel, <a href="/A143704/b143704.txt">Table of n, a(n) for n = 1..10000</a> %e A143704 a(8) = ( 7 + 3) * 5 = 10*5 = 50; %e A143704 a(9) = ( 2 + 4) * 17 = 102; %e A143704 a(10) = ( 2 + 3) * 2 = 10; %e A143704 a(11) = (19 + 2) * 2 = 42; %e A143704 a(12) = ( 5 + 3) * 7 = 56; %e A143704 a(13) = ( 2 + 11) * 23 = 199; %e A143704 etc. %p A143704 g:= proc(n) local L; L:= sort(ifactors(n)[2],(s,t) -> s[1]<t[1]); %p A143704 L:= map(proc(t) if t[2]=1 then t[1] else op(t) fi end proc, L); %p A143704 op(L); %p A143704 end proc: %p A143704 g(1):= 1: %p A143704 B:= map(g, [$1..100]): %p A143704 seq((B[3*i+1]+B[3*i+2])*B[3*i+3], i=0..(nops(B)-3)/3); # _Robert Israel_, Nov 16 2019 %Y A143704 Cf. A141287, A141261, A136735. %K A143704 nonn %O A143704 1,1 %A A143704 _Juri-Stepan Gerasimov_, Nov 13 2008 %E A143704 Corrected (199 replaced by 299, 60 replaced by 30, 549 replaced by 54 etc.) by _R. J. Mathar_, Apr 18 2010