OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..30
FORMULA
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
KEYWORD
nonn
AUTHOR
Labos Elemer, Apr 14 2003
STATUS
approved