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A111974
Primes of the form 2*3^k + 1.
8
3, 7, 19, 163, 487, 1459, 39367, 86093443, 258280327, 411782264189299, 116299474006080119380780339, 3140085798164163223281069127, 84782316550432407028588866403, 20602102921755074907947094535687
OFFSET
1,1
LINKS
Hartosh Singh Bal and Gaurav Bhatnagar, Prime number conjectures from the Shapiro class structure, arXiv:1903.09619 [math.NT], 2019.
MATHEMATICA
Select[2*3^Range[100]+1, PrimeQ]
CROSSREFS
Cf. A003306 (k such that 2*3^k + 1 is prime), A003307 (k such that 2*3^k - 1 is prime).
Sequence in context: A245723 A118128 A113875 * A243100 A173400 A281971
KEYWORD
nonn
AUTHOR
T. D. Noe, Aug 24 2005
STATUS
approved