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 A143273 #17 Jun 06 2023 04:19:55 %S A143273 1,2,4,3,6,6,4,8,8,12,5,10,10,15,10,6,12,12,18,12,24,7,14,14,21,14,28, %T A143273 14,8,16,16,24,16,32,16,32,9,18,18,27,18,36,18,36,27,10,20,20,30,20, %U A143273 40,20,40,30,40,11,22,22,33,22,44,22,44,33,44,22 %N A143273 Triangle read by rows: A127648 * A000012 * A130209. %C A143273 Row sums = A143274: (1, 6, 15, 32, 50, 84, ...). %F A143273 T(n,k) = n*d(k). %e A143273 First few rows of the triangle = %e A143273 1; %e A143273 2, 4; %e A143273 3, 6, 6; %e A143273 4, 8, 8, 12; %e A143273 5, 10, 10, 15, 10; %e A143273 6, 12, 12, 18, 12, 24; %e A143273 7, 14, 14, 21, 14, 28, 14; %e A143273 8, 16, 16, 24, 16, 32, 16, 32; %e A143273 ... %e A143273 T(6,3) = 12 = 6*d(3) = 6*2, where A000005 = d(k) = (1, 2, 3, 2, 2, 4, 2, 4, 3, ...). %o A143273 (PARI) tabl(nn) = for (n=1, nn, for (k=1, n, print1(n*numdiv(k), ", "))); \\ _Michel Marcus_, Mar 19 2016 %Y A143273 Cf. A000005, A127648, A130209, A143274. %K A143273 nonn,tabl %O A143273 1,2 %A A143273 _Gary W. Adamson_, Aug 03 2008 %E A143273 a(48) = 20 inserted by _Georg Fischer_, Jun 05 2023