A363034 - OEIS

%I #15 Jul 06 2023 07:30:17

%S 3,8,13,21,23,28,36,38,43,59,53,58,66,68,73,94,83,96,96,98,103,129,

%T 113,118,126,136,133,164,156,148,156,158,163,207,173,178,186,188,193,

%U 252,203,229,216,218,223,269,233,238,246,256,276,304,263,268,289,278,283,365,293,298,306,336,313,374,323

%N Sum of divisors of 5*n-2 of form 5*k+3.

%F a(n) = A284281(5*n-2).

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

%t a[n_] := DivisorSum[5*n - 2, # &, Mod[#, 5] == 3 &]; Array[a, 100] (* _Amiram Eldar_, Jul 06 2023 *)

%o (PARI) a(n) = sumdiv(5*n-2, d, (d%5==3)*d);

%Y Cf. A363033, A363035, A363053.

%Y Cf. A284281, A359236, A363156.

%K nonn

%O 1,1

%A _Seiichi Manyama_, Jul 06 2023