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

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

Offset: 1

Author

Felix Fröhlich, Aug 27 2016

Keywords

• nonn
• hard
• more

Comments

Numbers k such that A185277(k) is prime.

Examples

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

Links

• 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.

Crossrefs

Cf. A064539, A185277, A253471.

Programs

PARI

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