A366820 -id:A366820 - cp's OEIS frontend

A377673 a(n) is the sum of the divisors of n^n + n.

3, 12, 72, 588, 5652, 117504, 1895712, 46503600, 839411118, 25440307200, 474527311344, 22404560101168, 489294047662728, 30902868417576960, 1096805935992340800, 38000593697802058224, 1318965178069293272496, 90596485743469636057920, 3578317312662511683264000

Offset: 1

Sean A. Irvine, Nov 03 2024

nonn

Amiram Eldar, Table of n, a(n) for n = 1..116

Cf. A000203, A066068, A366820, A372228, A372546, A377671, A377672, A377674.

a[n_] := DivisorSigma[1, n^n + n]; Array[a, 20] (* Amiram Eldar, Nov 04 2024 *)

PARI
```
a(n) = sigma(n^n+n);
```

a(n) = A000203(A066068(n)).

A366819 a(n) is the sum of the divisors of n^n-1.

Original entry on oeis.org

4, 42, 432, 6048, 67584, 1704240, 38054016, 967814400, 16203253248, 513593801496, 15743437516800, 720045832568832, 19146847615988736, 835966563470742528, 31421980989189888768, 1602925310146310674200, 52064744760120508416000, 4286575920597346109768658

Offset: 2

Sean A. Irvine, Oct 24 2023

nonn

Amiram Eldar, Table of n, a(n) for n = 2..138

Cf. A000203, A048861, A309941, A344870, A334167, A062727, A366820.

Array[DivisorSigma[1, #^# - 1] &, 18, 2] (* Michael De Vlieger, Oct 24 2023 *)

PARI
```
a(n) = sigma(n^n-1);
```

a(n) = A000203(A048861(n)).

cp's OEIS Frontend

A377673 a(n) is the sum of the divisors of n^n + n.

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