A105049 a(n) is the smallest prime p such that p+n! is prime and p differs from all a(i), i

2, 3, 5, 7, 11, 13, 19, 23, 17, 41, 29, 43, 67, 71, 149, 73, 31, 37, 89, 53, 47, 127, 97, 131, 107, 59, 137, 101, 223, 163, 241, 79, 139, 103, 61, 577, 311, 151, 269, 173, 211, 167, 109, 191, 239, 521, 233, 83, 383, 337, 271, 827, 449, 443, 229, 157, 179, 283, 293, 277

Offset: 1

Author

R. J. Mathar, Aug 22 2007

Keywords

• nonn

Comments

A variant of A130807.

If the requirement is dropped that a(n) be distinct from earlier primes in the list, the sequence becomes 2, 3, 5, 5, 7, 7, 11, 23, 17, 11, 17, 29, 67, 19, 43, 23, 31, 37, 89,.. which presumably duplicates A037153.

Programs

Maple

A105049 := proc(nmin) local i,a,iused; a := [] ; iused := {} ; for n from 1 to nmin do i := 1; while not isprime(ithprime(i)+n!) or i in iused do i := i+1 ; od; iused := iused union {i} ; a := [op(a),ithprime(i)] ; od ; RETURN(a) ; end: A105049(80);