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A366580 Number of distinct prime divisors of 3^n + 1. 11
1, 1, 2, 2, 2, 2, 3, 2, 3, 4, 3, 3, 3, 2, 4, 5, 2, 4, 4, 3, 3, 5, 4, 2, 6, 4, 4, 6, 4, 4, 5, 3, 2, 6, 4, 4, 4, 4, 4, 7, 5, 3, 7, 2, 5, 9, 4, 4, 4, 4, 6, 8, 4, 3, 5, 6, 6, 7, 4, 3, 7, 3, 5, 11, 2, 4, 6, 3, 5, 8, 8, 6, 8, 3, 5, 11, 6, 5, 7, 4, 5, 11, 5, 5, 10, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
Max Alekseyev, Table of n, a(n) for n = 0..691
FORMULA
a(n) = omega(3^n+1) = A001221(A034472(n)).
MATHEMATICA
PrimeNu[3^Range[0, 100]+1] (* Paolo Xausa, Oct 14 2023 *)
PROG
(PARI) for(n = 0, 100, print1(omega(3^n + 1), ", "))
CROSSREFS
Cf. A001221, A002592, A034472, A046799, A057935, A057941, A074476, A133801, A274909, A366577, A366578, A366579.
Sequence in context: A147981 A051888 A327966 * A088019 A301508 A178930
Adjacent sequences: A366577 A366578 A366579 * A366581 A366582 A366583
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Oct 13 2023
STATUS
approved

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Last modified August 29 21:13 EDT 2024. Contains 375518 sequences. (Running on oeis4.)