A087202 a(n) is the smallest m such that m > A037153(n) and n!+ m is prime.

4, 5, 7, 7, 11, 13, 19, 31, 23, 19, 19, 43, 73, 41, 149, 41, 53, 61, 109, 37, 37, 71, 109, 193, 97, 173, 59, 101, 229, 163, 241, 83, 139, 103, 83, 577, 397, 47, 269, 61, 211, 107, 97, 89, 379, 149, 269, 83, 137, 167, 281, 89, 79, 443, 229, 157, 179, 563, 389, 277

Offset: 1

Author

Farideh Firoozbakht, Sep 01 2003

Keywords

• nonn

Comments

a(n) is the second m (first m is A037153(n)) such that m > 1 and n!+ m is prime.

Conjecture: For n > 1, a(n) is prime (compare the conjecture about A037153).

Conjecture holds through 1200 terms.

Links

• Ray Chandler, Table of n, a(n) for n=1..1200

Crossrefs

Cf. A037153, A005235, A087200.

Programs

Mathematica

A037153[n_] := (For[m=Prime[PrimePi[n]+1], !PrimeQ[n!+m], m++ ]; m); a[n_] := (For[m=A037153[n]+1, !PrimeQ[n!+m], m++ ]; m); Table[a[n], {n, 60}]

Extensions

Edited by Ray Chandler, Mar 08 2010