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A082102
Primes of the form 2^(k-1) + 3^k.
2
11, 31, 89, 761, 2251, 6689, 59561, 14365291, 10461401779, 282437925089, 150094669656737489, 239299329512092506300739, 2153693964201457673153371, 107752636643058216783050887908587014548761
OFFSET
1,1
LINKS
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
Sequence in context: A250461 A259508 A126365 * A199112 A299782 A027847
KEYWORD
nonn
AUTHOR
Labos Elemer, Apr 14 2003
STATUS
approved