A268065 Integers k such that 2^k + 3^k + 5^k + k is prime.

0, 1, 3, 7, 19, 33, 1363, 6663

Offset

1,3

Comments

Next term, if it exists, is greater than 30000. - Vaclav Kotesovec, Jan 26 2016

Links

Table of n, a(n) for n=1..8.

Example

k=3: 2^3+3^3+5^3+3 = 163.

Mathematica

Select[Range[0, 2000], PrimeQ[2^# + 3^# + 5^# + #] &] (* Vaclav Kotesovec, Jan 25 2016 *)

Prog

(PARI) lista(nn) = for(n=0, nn, if(ispseudoprime(2^n + 3^n + 5^n + n), print1(n, ", "))); \\ Altug Alkan, Jan 25 2016

Crossrefs

Cf. A076515, A268067.

Sequence in context: A112633 A113916 A227502 * A049490 A112391 A127928

Adjacent sequences: A268062 A268063 A268064 * A268066 A268067 A268068

Keyword

nonn,more

Author

Emre APARI, Jan 25 2016

Extensions

a(7) from Vaclav Kotesovec, Jan 25 2016

Status

approved