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%I #13 Jun 30 2023 15:36:11
%S 1,1,5,1,10,5,17,1,30,10,37,5,50,17,78,1,82,30,101,10,142,37,145,5,
%T 179,50,226,17,226,78,257,1,330,82,350,30,362,101,454,10,442,142,485,
%U 37,632,145,577,5,642,179,762,50,730,226,830,17,946,226,901,78,962,257,1191,1,1148,330,1157,82
%N Expansion of Sum_{k>0} k^2 * x^(2*k-1) / (1 - x^(2*k-1)).
%F a(n) = Sum_{d|n, d==1 mod 2} ((d+1)/2)^2.
%t a[n_] := DivisorSum[n, ((# + 1)/2)^2 &, OddQ[#] &]; Array[a, 100] (* _Amiram Eldar_, Jun 30 2023 *)
%o (PARI) a(n) = sumdiv(n, d, (d%2==1)*((d+1)/2)^2);
%Y Cf. A001227, A113415.
%Y Cf. A050999, A363974.
%K nonn,easy
%O 1,3
%A _Seiichi Manyama_, Jun 30 2023
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