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A255542
a(n) = number of prime factors of (3^n + 10) counted with multiplicity.
1
1, 1, 1, 1, 2, 2, 1, 3, 1, 2, 4, 3, 2, 3, 2, 3, 5, 3, 1, 3, 3, 3, 4, 2, 3, 4, 2, 6, 4, 3, 3, 4, 3, 2, 5, 4, 1, 4, 5, 5, 5, 2, 4, 3, 3, 5, 5, 2, 2, 5, 4, 3, 4, 3, 3, 6, 4, 4, 5, 5, 7, 3, 3, 4, 5, 5, 2, 6, 3, 5, 5, 4, 4, 5, 3, 7, 6, 4, 4, 3, 2, 4, 5, 4, 2, 4, 3, 2, 4, 4, 4, 5, 4, 6, 7, 4, 3, 5, 1, 4
OFFSET
0,5
LINKS
Amiram Eldar, Table of n, a(n) for n = 0..257 (terms 0..151 from Zak Seidov)
FORMULA
a(n) = A001222(3^n+10).
EXAMPLE
a(0) = 1 because 3^0+10 = 11 is prime.
a(4) = 2 because 3^4+10 = 91 = 7*13 is semiprime.
a(7) = 3 because 3^7+10 = 2197 = 13*13*13 is 3-almost prime.
a(10) = 4 because 3^7+10 = 59059 = 7*11*13*59 is 4-almost prime.
a(16) = 5 because 3^16+10 = 43046731 = 7*13*23*131*157 is 5-almost prime.
MATHEMATICA
a[n_]:= PrimeOmega[3^n+10];
PROG
(PARI) a(n) = bigomega(3^n+10);
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Feb 25 2015
STATUS
approved