cp's OEIS Frontend

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.

A143271 Triangle read by rows: A130209 * A000012 * A127648.

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%I A143271 #11 Jun 05 2023 21:20:15
%S A143271 1,2,4,2,4,6,3,6,9,12,2,4,6,8,10,4,8,12,16,20,24,2,4,6,8,10,12,14,4,8,
%T A143271 12,16,20,24,28,32,3,6,9,12,15,18,21,24,27,4,8,12,16,20,24,28,32,36,
%U A143271 40,2,4,6,8,10,12,14,16,18,20,22,6,12,18,24,30,36,42,48,54,60,66,72
%N A143271 Triangle read by rows: A130209 * A000012 * A127648.
%C A143271 Row sums = A143272: (1, 6, 12, 30, 30, 84, 56, ...).
%C A143271 Left border = A000005: (1, 2, 2, 3, 2, 4, 2, 4, 3, ...).
%F A143271 T(n,k) = d(n)*k.
%e A143271 First few rows of the triangle =
%e A143271   1;
%e A143271   2, 4;
%e A143271   2, 4,  6;
%e A143271   3, 6,  9, 12;
%e A143271   2, 4,  6,  8, 10;
%e A143271   4, 8, 12, 16, 20, 24;
%e A143271   2, 4,  6,  8, 10, 12, 14;
%e A143271   ...
%e A143271 T(5,3) = 6 = 2*3 = d(5)*3.
%o A143271 (PARI) tabl(nn) = for (n=1, nn, for (k=1, n, print1(numdiv(n)*k, ", "))); \\ _Michel Marcus_, Jun 05 2023
%Y A143271 Cf. A000005, A127648, A130209, A143272.
%K A143271 nonn,tabl
%O A143271 1,2
%A A143271 _Gary W. Adamson_, Aug 03 2008
%E A143271 a(62) corrected by _Georg Fischer_, Jun 05 2023