A069346 Primes of the form n - Omega(n), where Omega(n) is the number of prime factors of n, A001222(n).

2, 5, 7, 13, 17, 19, 23, 31, 37, 41, 43, 47, 53, 67, 73, 83, 89, 103, 107, 109, 113, 127, 131, 139, 151, 157, 163, 167, 179, 181, 199, 211, 227, 233, 239, 241, 251, 257, 263, 281, 283, 293, 307, 311, 313, 317, 337, 347, 353, 359

Offset: 1

Author

Reinhard Zumkeller, Mar 18 2002

Keywords

• nonn

Comments

The representation is ambiguous, see A069347.

Examples

			a(10) = 41 = A069345(44) = 44-3 (as 44 = 2*2*11).
		

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A069348, A069356.

Programs

Mathematica

Select[Table[n - PrimeOmega[n], {n, 1, 400}], PrimeQ] // Union (* Jean-François Alcover, Jun 08 2013 *)

PARI

is(n)=for(k=1, log(n)\log(2)+1, if(bigomega(n+k)==k, return(isprime(n)))); 0 \\ Charles R Greathouse IV, Dec 10 2013