A378309 - OEIS

A378309

a(n) = A010051(n) + A001222(n).

0, 2, 2, 2, 2, 2, 2, 3, 2, 2, 2, 3, 2, 2, 2, 4, 2, 3, 2, 3, 2, 2, 2, 4, 2, 2, 3, 3, 2, 3, 2, 5, 2, 2, 2, 4, 2, 2, 2, 4, 2, 3, 2, 3, 3, 2, 2, 5, 2, 3, 2, 3, 2, 4, 2, 4, 2, 2, 2, 4, 2, 2, 3, 6, 2, 3, 2, 3, 2, 3, 2, 5, 2, 2, 3, 3, 2, 3, 2, 5, 4, 2, 2, 4, 2, 2, 2, 4, 2, 4

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Paolo Xausa, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = A113903(n) - A113903(n-1).

a(n) = 2 for prime n.

a(2*k) = A073093(k), for k >= 2.

MATHEMATICA

Array[Boole[PrimeQ[#]] + PrimeOmega[#] &, 100]

PROG