A276203 Numbers k such that k^9 + 9^k is prime.

2, 76, 122, 422, 2300, 5090, 7166, 58046, 91382, 234178, 314738

Offset

1,1

Comments

Numbers k such that A185277(k) is prime.

Links

Table of n, a(n) for n=1..11.

Hans Havermann, Indices of A094133 in A076980.

Andrey V. Kulsha, Factorizations of x^y + y^x for 1 < y < x < 151.

P. Leyland, Primes and Strong Pseudoprimes of the form x^y + y^x.

Example

2 is a term of the sequence, because A185277(2) = 593 is prime.

Prog

(PARI) is(n) = ispseudoprime(n^9+9^n)

Crossrefs

Cf. A064539, A185277, A253471.

Sequence in context: A282966 A351433 A351376 * A324216 A198704 A198623

Adjacent sequences: A276200 A276201 A276202 * A276204 A276205 A276206

Keyword

nonn,hard,more

Author

Felix Fröhlich, Aug 27 2016

Status

approved