A130536 Prime numbers arising from A057856.

3, 5, 7, 41, 11, 13, 113, 17, 19, 2211377674535255285545615254209921, 23, 313, 66977, 29, 31, 149057, 613, 37, 761, 41, 43, 1013, 47, 1201, 1301, 53, 1146097

Offset

1,1

Comments

Conjecture: For all pairs of relative prime numbers (x, y) there exists at least one number n = 2^m and one prime number p such that p = x^n + y^n. This sequence shows one case of this conjecture where y = x + 1.

Links

Table of n, a(n) for n=1..27.

Example

a(10)=2211377674535255285545615254209921 because A057856(10)=32 and 2211377674535255285545615254209921 = 10^32 + 11^32 = 100000000000000000000000000000000 + 2111377674535255285545615254209921.

Prog

(PARI) a(n) = my(k=1); while (!isprime(p=(n+1)^k + n^k), k++); p; \\ Michel Marcus, Sep 16 2018

Crossrefs

Cf. A057856.

Sequence in context: A037287 A163797 A339900 * A261511 A146972 A102742

Adjacent sequences: A130533 A130534 A130535 * A130537 A130538 A130539

Keyword

nonn,hard

Author

Tomas Xordan, Jun 02 2007

Status

approved