A082876 Number of prime divisors (counted with multiplicity) of numbers of form a^n + b^n + c^n + ..., where a*b*c* ... is the prime factorization of n.

0, 2, 3, 5, 5, 2, 7, 9, 10, 3, 11, 1, 13, 5, 7, 18, 17, 4, 19, 3, 7, 7, 23, 3, 26, 6, 28, 3, 29, 4, 31, 33, 8, 5, 11, 6, 37, 7, 9, 3, 41, 5, 43, 5, 4, 7, 47, 5, 50, 8, 14, 7, 53, 5, 11, 4, 8, 9, 59, 4, 61, 9, 5, 66, 11, 4, 67, 7, 11, 11, 71, 7, 73, 9, 4

Offset

1,2

Comments

A082872(2) and A082872(6) are semiprimes. Where is the next?

Links

Table of n, a(n) for n=1..75.

Prog

(PARI) a(n) = if(n<2, 0, bigomega(sum(i=1, matsize(f=factor(n))[1], f[i, 1]^n*f[i, 2]))); \\ Jinyuan Wang, Apr 01 2020

Crossrefs

Cf. A001222, A082813, A082814, A082872.

Sequence in context: A175210 A264047 A264035 * A096099 A019780 A227833

Adjacent sequences: A082873 A082874 A082875 * A082877 A082878 A082879

Keyword

nonn,more

Author

Jason Earls, May 25 2003

Extensions

a(74)-a(75) from Jinyuan Wang, Apr 01 2020

Status

approved