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 A322264 #4 Dec 19 2018 13:34:23
%S A322264 1,1,1,1,2,1,1,4,3,1,1,8,9,4,1,1,16,27,16,5,1,1,32,81,64,25,1,1,1,64,
%T A322264 243,256,125,18,7,1,1,128,729,1024,625,6,49,8,1,1,256,2187,4096,3125,
%U A322264 648,343,64,9,1,1,512,6561,16384,15625,648,2401,512,81,5,1,1,1024,19683,65536,78125,23328,16807,4096,729,10,11,1
%N A322264 Square array A(n,k), n >= 1, k >= 0, read by antidiagonals: A(n,k) = denominator of Sum_{d|n} 1/d^k.
%H A322264 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A322264 G.f. of column k: Sum_{j>=1} x^j/(j^k*(1 - x^j)) (for rationals Sum_{d|n} 1/d^k).
%F A322264 Dirichlet g.f. of column k: zeta(s)*zeta(s+k) (for rationals Sum_{d|n} 1/d^k).
%F A322264 A(n,k) = denominator of sigma_k(n)/n^k.
%e A322264 Square array begins:
%e A322264 1, 1, 1, 1, 1, 1, ...
%e A322264 2, 3/2, 5/4, 9/8, 17/16, 33/32, ...
%e A322264 2, 4/3, 10/9, 28/27, 82/81, 244/243, ...
%e A322264 3, 7/4, 21/16, 73/64, 273/256, 1057/1024, ...
%e A322264 2, 6/5, 26/25, 126/125, 626/625, 3126/3125, ...
%e A322264 4, 2, 25/18, 7/6, 697/648, 671/648, ...
%t A322264 Table[Function[k, Denominator[DivisorSigma[-k, n]]][i - n], {i, 0, 12}, {n, 1, i}] // Flatten
%t A322264 Table[Function[k, Denominator[DivisorSigma[k, n]/n^k]][i - n], {i, 0, 12}, {n, 1, i}] // Flatten
%t A322264 Table[Function[k, Denominator[SeriesCoefficient[Sum[x^j/(j^k (1 - x^j)), {j, 1, n}], {x, 0, n}]]][i - n], {i, 0, 12}, {n, 1, i}] // Flatten
%Y A322264 Columns k=0..24 give A000012, A017666, A017668, A017670, A017672, A017674, A017676, A017678, A017680, A017682, A017684, A017686, A017688, A017690, A017692, A017694, A017696, A017698, A017700, A017702, A017704, A017706, A017708, A017710, A017712.
%Y A322264 Numerators are in A322263.
%Y A322264 Cf. A109974, A279394.
%K A322264 nonn,tabl,frac
%O A322264 1,5
%A A322264 _Ilya Gutkovskiy_, Dec 01 2018