A366632 - OEIS

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A366632

Number of distinct prime divisors of 7^n - 1.

11

2, 2, 3, 3, 3, 4, 4, 4, 5, 5, 4, 7, 3, 6, 6, 6, 4, 7, 4, 8, 6, 6, 5, 11, 5, 5, 9, 8, 5, 10, 5, 8, 8, 5, 7, 11, 5, 6, 7, 11, 5, 11, 4, 10, 10, 6, 4, 14, 8, 8, 9, 8, 5, 12, 6, 13, 8, 6, 6, 17, 6, 8, 9, 11, 9, 13, 6, 9, 9, 15, 4, 18, 7, 7, 10, 8, 9, 13, 4, 16, 13

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OFFSET

1,1

LINKS

Max Alekseyev, Table of n, a(n) for n = 1..388

FORMULA

a(n) = omega(7^n-1) = A001221(A024075(n)).

PROG

(PARI) for(n = 1, 100, print1(omega(7^n - 1), ", "))

CROSSREFS

Cf. A024075, A001221, A057954, A059889, A074249, A218358, A366620, A366633, A366634, A366635.

Cf. A046800, A133801, A366604, A366611, A366620, A366651, A366660, A102347, A366681, A366707.

Sequence in context: A005707 A087828 A330779 * A110867 A342010 A006670

Adjacent sequences: A366629 A366630 A366631 * A366633 A366634 A366635

KEYWORD

nonn

AUTHOR

Sean A. Irvine, Oct 14 2023

STATUS

approved