A377677 a(n) is the sum of the divisors of n^n - n.

3, 60, 728, 10416, 116064, 2837120, 36990720, 1452853584, 27615698352, 965243666880, 23861701899840, 1355882884941312, 20758574413420992, 1604569397488307712, 93340493714183159808, 3135286584767445151680, 90560273718863022770592, 8284620870197084160000000

Offset

2,1

Links

Amiram Eldar, Table of n, a(n) for n = 2..115

Formula

a(n) = A000203(A061190(n)).

Mathematica

a[n_] := DivisorSigma[1, n^n - n]; Array[a, 20, 2] (* Amiram Eldar, Nov 04 2024 *)

Prog

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

Crossrefs

Cf. A000203, A061190, A366819, A377673, A377675, A377676, A377678.

Sequence in context: A006432 A360577 A195550 * A144659 A115490 A065889

Adjacent sequences: A377674 A377675 A377676 * A377678 A377679 A377680

Keyword

nonn,new

Author

Sean A. Irvine, Nov 03 2024

Status

approved