%I #30 Jul 06 2023 07:30:36

%S 0,3,0,8,3,13,0,21,0,23,3,36,0,36,0,38,3,43,13,59,0,53,3,58,0,84,0,76,

%T 3,73,0,94,23,83,3,96,0,96,0,126,3,103,0,137,13,113,36,118,0,126,0,

%U 136,3,171,0,164,0,156,3,156,43,174,0,158,3,163,0,255,0,173,16,178,0,186,53,196,3,193,23,252

%N Sum of divisors of 5*n-4 of form 5*k+3.

%F a(n) = A284281(5*n-4).

%F G.f.: Sum_{k>0} (5*k-2) * x^(2*k) / (1 - x^(5*k-2)).

%t a[n_] := DivisorSum[5*n - 4, # &, Mod[#, 5] == 3 &]; Array[a, 100] (* _Amiram Eldar_, Jul 06 2023 *)

%o (PARI) a(n) = sumdiv(5*n-4, d, (d%5==3)*d);

%Y Cf. A363033, A363034, A363035.

%Y Cf. A284281, A359244, A363158.

%K nonn

%O 1,2

%A _Seiichi Manyama_, Jul 06 2023