A082102 Primes of the form 2^(k-1) + 3^k.

11, 31, 89, 761, 2251, 6689, 59561, 14365291, 10461401779, 282437925089, 150094669656737489, 239299329512092506300739, 2153693964201457673153371, 107752636643058216783050887908587014548761

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..30

Formula

a(n) = 2^(A082103(n)-1) + 3^A082103(n). - Amiram Eldar, Aug 16 2024

Example

89 = 2^3 + 3^4.

Mathematica

Do[s=2^(w-1)+3^w; If[PrimeQ[s], Print[s]], {w, 1, 2000}]
Select[Table[2^(n-1)+3^n, {n, 100}], PrimeQ] (* Harvey P. Dale, Feb 09 2016 *)

Prog

(PARI) lista(kmax) = {my(p); for(k = 1, kmax, p = 2^(k-1) + 3^k; if(isprime(p), print1(p, ", "))); } \\ Amiram Eldar, Aug 16 2024

Crossrefs

Cf. A082101, A082103.

Sequence in context: A250461 A259508 A126365 * A199112 A299782 A027847

Adjacent sequences: A082099 A082100 A082101 * A082103 A082104 A082105

Keyword

nonn

Author

Labos Elemer, Apr 14 2003

Status

approved