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 A368810 #15 Feb 05 2024 03:49:22
%S A368810 2,6,11,50,137,147,363,1522,7129,7381,83711,86021,1145993,1171733,
%T A368810 1195757,4873118,42142223,42822903,275295799,279175675,56574159,
%U A368810 19093197,444316699,1347822955,34052522467,34395742267,312536252003,315404588903,9227046511387
%N A368810 a(n) = numerator of Sum_{i=1..n} Sum_{j=1..n} (1/i + 1/j).
%t A368810 Numerator[Table[Sum[Sum[1/i + 1/j, {i, 1, n}], {j, 1, n}], {n, 1, 29}]]
%o A368810 (Python)
%o A368810 from sympy import harmonic
%o A368810 def A368810(n): return ((n<<1)*harmonic(n)).p # _Chai Wah Wu_, Feb 04 2024
%Y A368810 Cf. A027611, A096620 (denominators), A193758.
%K A368810 nonn,frac
%O A368810 1,1
%A A368810 _Mats Granvik_, Jan 06 2024