A096986 Numbers k such that k*k! + (smallest prime > k) is prime.

1, 2, 3, 4, 5, 6, 7, 8, 23, 29, 30, 31, 40, 164, 176, 189, 218, 370, 597, 603, 1473, 1901, 2176, 2436, 2548, 2732, 4758, 5574

Offset

1,2

Comments

Note that Maple, PARI etc. have different notions of what "next prime" means!

Next term is > 7500. - Jacques Tramu, Sep 12 2018

Next term is > 10^4. - Michael S. Branicky, Aug 09 2024

Links

Table of n, a(n) for n=1..28.

Example

8 is in the sequence because 8*8!+ 11 is prime.

Mathematica

<< NumberTheory`NumberTheoryFunctions`; v={}; Do[If[PrimeQ [n*n!+NextPrime[n]], v=Append[v, n]; Print[v]], {n, 2400}]

Prog

(PARI) isok(n) = isprime(n*n! + nextprime(n+1)); \\ Michel Marcus, Sep 13 2018

Crossrefs

Cf. A096985, A090704, A049433, A108270

Sequence in context: A269355 A269357 A335900 * A031097 A162234 A024651

Adjacent sequences: A096983 A096984 A096985 * A096987 A096988 A096989

Keyword

more,nonn

Author

Farideh Firoozbakht, Jul 31 2004

Extensions

a(24)-a(27) from Jacques Tramu, Sep 12 2018

a(24) corrected by Michael S. Branicky, Aug 09 2024

Status

approved