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A232011 Numbers n such that (3n)^2 + 2 is prime. 2
1, 3, 5, 7, 11, 13, 15, 19, 27, 33, 35, 37, 39, 41, 49, 57, 73, 75, 79, 81, 83, 85, 91, 99, 101, 103, 107, 115, 117, 121, 123, 125, 129, 139, 141, 143, 147, 149, 151, 159, 167, 171, 183, 185, 187, 191, 201, 203, 217, 225, 227, 233, 237, 251, 259, 269, 273, 279 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Corresponding values of such primes are in A056899(n) for n>2.

Supersequence of A126960 (primes p such that (3p)^2 + 2 is prime).

LINKS

Jaroslav Krizek, Table of n, a(n) for n = 1..1000

FORMULA

a(n) = sqrt(A056899(n+2) - 2)/3 = A067201(n+2)/3.

EXAMPLE

7 is in sequence because (3*7)^2 + 2 = 443 (prime).

MATHEMATICA

Select[Range[279], PrimeQ[9 #^2 + 2] &] (* T. D. Noe, Nov 27 2013 *)

PROG

(PARI) is(n)=isprime(9*n^2+2) \\ Charles R Greathouse IV, Nov 25 2013

CROSSREFS

Cf. A000040, A056899, A067201, A126960.

Sequence in context: A316625 A091892 A292939 * A153183 A247648 A117203

Adjacent sequences:  A232008 A232009 A232010 * A232012 A232013 A232014

KEYWORD

nonn

AUTHOR

Jaroslav Krizek, Nov 25 2013

STATUS

approved

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Last modified August 25 13:50 EDT 2019. Contains 326324 sequences. (Running on oeis4.)