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a(n) = numerator of Sum_{i=1..n} Sum_{j=1..n} (1/i + 1/j).
1

%I #15 Feb 05 2024 03:49:22

%S 2,6,11,50,137,147,363,1522,7129,7381,83711,86021,1145993,1171733,

%T 1195757,4873118,42142223,42822903,275295799,279175675,56574159,

%U 19093197,444316699,1347822955,34052522467,34395742267,312536252003,315404588903,9227046511387

%N a(n) = numerator of Sum_{i=1..n} Sum_{j=1..n} (1/i + 1/j).

%t Numerator[Table[Sum[Sum[1/i + 1/j, {i, 1, n}], {j, 1, n}], {n, 1, 29}]]

%o (Python)

%o from sympy import harmonic

%o def A368810(n): return ((n<<1)*harmonic(n)).p # _Chai Wah Wu_, Feb 04 2024

%Y Cf. A027611, A096620 (denominators), A193758.

%K nonn,frac

%O 1,1

%A _Mats Granvik_, Jan 06 2024