A109302 Values of k such that prime(k)!+prime(k+1) is prime.

1, 2, 3, 4, 21, 93

Offset

1,2

Comments

The primes of the form prime(n)!+prime(n+1) are in A094108.

If it exists, a(7) > 1397. - J.W.L. (Jan) Eerland, Nov 27 2022

Links

Table of n, a(n) for n=1..6.

Example

4 is in the sequence because prime(4)=7, prime(5)=11 and 7!+11=5051 is prime.

Maple

a:=proc(n) if isprime(ithprime(n)!+ithprime(n+1))=true then n else fi end: seq(a(n), n=1..50);

Mathematica

Select[Range[100], PrimeQ[Prime[#]!+Prime[#+1]]&] (* Harvey P. Dale, Jun 21 2021 *)

Prog

(PARI) isok(n) = isprime(prime(n)!+prime(n+1)); \\ Michel Marcus, Aug 20 2019

Crossrefs

Cf. A094108.

Sequence in context: A058780 A183458 A109787 * A081480 A070841 A069801

Adjacent sequences: A109299 A109300 A109301 * A109303 A109304 A109305

Keyword

nonn,more

Author

Emeric Deutsch, Jun 24 2005

Status

approved