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A199191 n such that 3^(2n-3)+3^(n-1)+1 is prime. 2
2, 3, 4, 5, 6, 10, 11, 41, 83, 160, 178, 526, 881, 2578, 3772 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

n such that A198410(n) is prime.

LINKS

Table of n, a(n) for n=1..15.

MATHEMATICA

Select[Range[250], PrimeQ[((3^(#-1) + 1)^3 -1)/3^#]&]

CROSSREFS

Cf. A198410, A199192.

Sequence in context: A212774 A131934 A066501 * A102570 A113007 A113325

Adjacent sequences:  A199188 A199189 A199190 * A199192 A199193 A199194

KEYWORD

nonn,hard

AUTHOR

Michel Lagneau, Nov 03 2011

STATUS

approved

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Last modified February 27 19:23 EST 2020. Contains 332308 sequences. (Running on oeis4.)