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A111251 Numbers n such that 3*n^2 + 3*n + 1 is prime. 3
1, 2, 3, 4, 6, 9, 10, 11, 13, 14, 17, 23, 24, 25, 27, 28, 30, 32, 34, 37, 38, 41, 42, 45, 48, 49, 52, 55, 58, 62, 63, 66, 67, 74, 80, 81, 86, 88, 90, 91, 93, 95, 105, 108, 119, 123, 125, 128, 129, 136, 140, 142, 147, 153, 156, 157, 158, 164, 165, 170, 171, 172, 175 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Also n such that (n+1)^3-n^3 is prime so prime difference of two consecutive cubes.

LINKS

Pierre CAMI, Table of n, a(n) for n = 1..1965

EXAMPLE

If n=52 then 3*n^2 + 3*n + 1 = 8269 (prime).

MATHEMATICA

Select[Range[200], PrimeQ[3#^2+3#+1]&] (* Harvey P. Dale, May 29 2017 *)

PROG

(PARI) for(n=0, 250, if(isprime(3*n^2+3*n+1), print1(n, ", ")))

CROSSREFS

Sequence in context: A047419 A135205 A145733 * A047300 A026439 A285082

Adjacent sequences:  A111248 A111249 A111250 * A111252 A111253 A111254

KEYWORD

nonn

AUTHOR

Parthasarathy Nambi, Oct 31 2005

EXTENSIONS

Extended by Lambert Klasen (lambert.klasen(AT)gmx.net), Nov 02 2005

STATUS

approved

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Last modified February 22 23:03 EST 2019. Contains 320411 sequences. (Running on oeis4.)