A220788 Numbers n such that 7^n + 6^n is prime.

0, 1, 4, 16

Offset

1,3

Comments

Next term is > 15000 if it exists.

Links

Table of n, a(n) for n=1..4.

Mathematica

Join[{0, 1}, Select[2 Range[500], PrimeQ[7^# + 6^#] &]]

Prog

(Magma) /* The program does not work for n>2700: */ [n: n in [0..1000]| IsPrime(7^n + 6^n)];
(PARI) for(n=0, 1000, if(isprime(7^n + 6^n), print1(n, ", ")))

Crossrefs

Cf. A062573, A074619.

Sequence in context: A070037 A297859 A298127 * A330315 A061849 A052107

Adjacent sequences: A220785 A220786 A220787 * A220789 A220790 A220791

Keyword

nonn,more

Author

Vincenzo Librandi, Jan 10 2013

Status

approved