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A102657 Numbers n such that 11n^2 + 11n + 1 is prime. 0
1, 2, 5, 6, 7, 9, 11, 13, 14, 20, 23, 25, 26, 27, 28, 32, 33, 36, 37, 40, 42, 48, 49, 50, 51, 58, 61, 62, 68, 74, 75, 76, 77, 78, 81, 84, 92, 96, 103, 104, 109, 111, 119, 120, 126, 127, 133, 135, 137, 141, 142, 144, 145, 149, 153, 156, 158, 163, 166, 168, 169, 172, 176 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..63.

EXAMPLE

For n=1,  11n^2 + 11n + 1 = 11*1^2  + 11*1  + 1 = 23 (prime);

for n=20, 11n^2 + 11n + 1 = 11*20^2 + 11*20 + 1 = 4621 (prime);

for n=40, 11n^2 + 11n + 1 = 11*40^2 + 11*40 + 1 = 18041 (prime).

MATHEMATICA

Select[Range[200], PrimeQ[11#^2+11#+1]&] (* Harvey P. Dale, Aug 15 2012 *)

PROG

(MAGMA) [n: n in [0..1000] | IsPrime(11*n^2+11*n+1)] // Vincenzo Librandi, Nov 17 2010]

(PARI) is(n)=isprime(11*n^2+11*n+1) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A177859 A047580 A153384 * A202115 A047324 A327184

Adjacent sequences:  A102654 A102655 A102656 * A102658 A102659 A102660

KEYWORD

nonn,easy

AUTHOR

Parthasarathy Nambi, Feb 02 2005

STATUS

approved

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Last modified September 20 11:01 EDT 2020. Contains 337264 sequences. (Running on oeis4.)