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%I #14 Jul 17 2023 00:59:54
%S 0,4,0,9,0,18,0,19,0,28,0,29,9,38,0,39,0,48,0,63,0,67,0,59,0,68,19,69,
%T 0,78,9,79,0,126,0,89,0,98,0,108,29,108,0,109,0,137,0,167,9,128,0,129,
%U 0,138,39,139,0,181,0,149,0,216,0,159,19,168,9,169,49,207,0,179,0,188,0,266,0,198,0
%N Sum of divisors of 5*n-2 of form 5*k+4.
%F a(n) = A284103(5*n-2).
%F G.f.: Sum_{k>0} (5*k-1) * x^(2*k) / (1 - x^(5*k-1)).
%t a[n_] := DivisorSum[5*n - 2, # &, Mod[#, 5] == 4 &]; Array[a, 100] (* _Amiram Eldar_, Jul 17 2023 *)
%o (PARI) a(n) = sumdiv(5*n-2, d, (d%5==4)*d);
%Y Cf. A364100, A364102, A364103.
%Y Cf. A284103, A359269, A364105.
%K nonn
%O 1,2
%A _Seiichi Manyama_, Jul 04 2023