A309941 Number of prime factors of n^n - 1, counted with multiplicity.

1, 2, 3, 4, 4, 4, 7, 8, 6, 4, 8, 6, 5, 7, 7, 7, 10, 4, 11, 10, 8, 6, 13, 13, 11, 9, 13, 10, 15, 4, 13, 12, 13, 10, 18, 11, 8, 10, 16, 9, 16, 6, 15, 18, 9, 5, 19, 20, 14, 15, 17, 8, 16, 12, 18, 10, 10, 5, 26, 8, 10, 14, 20, 19, 17, 9, 17, 12, 19, 7, 29, 15, 8, 11, 20, 13, 21, 8

Offset

2,2

Links

Chai Wah Wu, Table of n, a(n) for n = 2..126

factordb, Factors of n^n-1.

Example

a(3) = 2: 3^3 - 1 = 26 = 2 * 13,
a(5) = 4: 5^5 - 1 = 3124 = 2^2 * 11 * 71.

Prog

(PARI) for(k=2, 50, print1(bigomega(k^k-1), ", "))

Crossrefs

Cf. A006486, A048861, A085723, A116895, A125135.

Sequence in context: A057951 A076410 A361164 * A352457 A211509 A305594

Adjacent sequences: A309938 A309939 A309940 * A309942 A309943 A309944

Keyword

nonn,hard

Author

Hugo Pfoertner, Aug 24 2019

Status

approved