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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
OFFSET
0,3
LINKS
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), ", "))
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Oct 13 2023
STATUS
approved