A364094 Sum of divisors of 5*n-3 of form 5*k+1.
1, 1, 7, 1, 12, 1, 17, 1, 28, 1, 27, 1, 32, 1, 43, 12, 42, 1, 47, 1, 58, 1, 73, 1, 62, 1, 84, 1, 72, 22, 77, 1, 88, 1, 87, 1, 118, 12, 119, 1, 102, 1, 107, 32, 118, 1, 117, 1, 133, 1, 190, 1, 132, 1, 153, 1, 148, 42, 147, 12, 152, 1, 189, 1, 208, 1, 167, 1, 178, 1, 204, 73, 182, 1, 224, 1, 192, 1
Offset: 1
Keywords
Programs
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Mathematica
a[n_] := DivisorSum[5*n - 3, # &, Mod[#, 5] == 1 &]; Array[a, 100] (* Amiram Eldar, Jul 17 2023 *)
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PARI
a(n) = sumdiv(5*n-3, d, (d%5==1)*d);
Formula
a(n) = A284097(5*n-3).
G.f.: Sum_{k>0} (5*k-4) * x^(2*k-1) / (1 - x^(5*k-4)).