A332849 a(n) = prime(n)^prime(n+1) + prime(n) + prime(n+1).

13, 251, 78137, 1977326761, 34522712143955, 8650415919381337963, 239072435685151324847189, 257829627945307727248226067301, 3091058643093537522799545838540043339115, 2159424054808578564166497528588784562372597489, 15148954872646847105498509334067131813327318808179940579

Offset: 1

Author

J. M. Bergot and Robert Israel, Feb 26 2020

Keywords

• nonn

Comments

a(n) is prime for n = 1,2,3,4, but for no other n < 500.

On the other hand, prime(n+1)^prime(n)+prime(n)+prime(n+1) is not prime for n < 500. - Robert Israel, Feb 27 2020

Examples

			a(3) = 5^7 + 5 + 7 = 78137.
		

Links

• Robert Israel, Table of n, a(n) for n = 1..75

Crossrefs

Cf. A001043, A000040, A053089.

Programs

Maple

seq(ithprime(i)^ithprime(i+1)+ithprime(i)+ithprime(i+1),i=1..20);

Mathematica

Map[#[[1]]^#[[2]]+Total[#]&,Partition[Prime[Range[15]],2,1]] (* Paolo Xausa, Nov 02 2023 *)

Formula

a(n) = A053089(n) + A001043(n). - Omar E. Pol, Feb 26 2020