%I #15 Jul 12 2023 01:01:49

%S 1,7,12,17,22,27,32,43,42,47,52,57,62,84,72,77,82,87,92,119,102,107,

%T 112,117,133,154,132,137,142,147,152,189,162,167,172,204,182,224,192,

%U 197,202,207,212,259,222,227,264,237,242,294,252,273,262,267,272,329,282,324,292,297,302,364,312

%N Sum of divisors of 5*n-4 of form 5*k+1.

%F a(n) = A284097(5*n-4).

%F G.f.: Sum_{k>0} (5*k-4) * x^k / (1 - x^(5*k-4)).

%t a[n_] := DivisorSum[5*n - 4, # &, Mod[#, 5] == 1 &]; Array[a, 100] (* _Amiram Eldar_, Jul 12 2023 *)

%o (PARI) a(n) = sumdiv(5*n-4, d, (d%5==1)*d);

%Y Cf. A364092, A364093, A364094.

%Y Cf. A284097, A359238, A364099.

%K nonn

%O 1,2

%A _Seiichi Manyama_, Jul 04 2023