A155771 -id:A155771 - cp's OEIS frontend

A155770 Primes of form: 2n^2+2n-41.

19, 43, 71, 103, 139, 179, 223, 271, 379, 439, 503, 571, 643, 719, 883, 971, 1063, 1259, 1471, 1583, 1699, 2203, 2339, 3079, 3571, 3919, 4099, 4283, 4663, 5059, 5471, 5683, 6343, 6571, 6803, 7039, 7523, 8539, 8803, 9343, 9619, 11059, 11971, 12919, 13903

Offset: 1

Vincenzo Librandi, Jan 27 2009

			19 is in this sequence because 2*5^2+2*5-41=19.

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Cf. A155769, A155771, A155772.

[a: n in [4..100] | IsPrime(a) where a is  2*n^2+2*n-41 ]; // Vincenzo Librandi, Sep 11 2013

Select[Table[2 n^2 + 2 n - 41, {n, 4, 100}], PrimeQ] (* Vincenzo Librandi, Sep 11 2013 *)

is(n)=isprime(2*n^2+2*n-41) \\ Charles R Greathouse IV, Sep 11 2013

A155772 Primes p such that 2p^2+2p-41 is a prime.

Original entry on oeis.org

5, 7, 11, 17, 19, 23, 29, 53, 59, 61, 83, 101, 103, 107, 131, 151, 179, 181, 191, 193, 199, 227, 239, 269, 281, 293, 313, 367, 383, 389, 419, 439, 467, 487, 503, 521, 541, 569, 587, 599, 601, 607, 617, 641, 647, 653, 673, 677, 691, 709, 733, 739, 757, 769, 787

Offset: 1

Vincenzo Librandi, Jan 27 2009

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Cf. A155769, A155770, A155771.

[p: p in PrimesInInterval(5, 800) | IsPrime(2*p^2 + 2*p - 41)]; // Vincenzo Librandi, Oct 15 2012

Select[Prime[Range[3, 200]], PrimeQ[2 #^2 + 2 # - 41] &] (* Vincenzo Librandi, Oct 15 2012 *)

A241264 Numbers k such that 2k^2 + 2k - 41 is not a prime.

Original entry on oeis.org

4, 13, 20, 24, 26, 30, 31, 32, 35, 36, 37, 38, 40, 41, 43, 47, 49, 51, 54, 55, 60, 62, 63, 64, 67, 70, 71, 72, 73, 75, 76, 78, 79, 81, 82, 84, 85, 88, 89, 92, 94, 97, 98, 100, 102, 105, 108, 109, 111, 112, 113, 114, 115, 117, 118, 119, 120, 122, 123, 124, 125

Offset: 1

Vincenzo Librandi, Apr 20 2014

			13 is in this sequence because 2*13^2 + 2*13 - 41 = 323 = 17*19.

Vincenzo Librandi, Table of n, a(n) for n = 1..5000

Complement of A155771.

[n: n in [1..150] | not IsPrime(2*n^2+2*n-41)];

Select[Range[4, 200], ! PrimeQ[2 #^2 + 2 # - 41] &]

cp's OEIS Frontend

A155770 Primes of form: 2n^2+2n-41.

Views

Author

Keywords

Examples

Links

Crossrefs

Programs

Magma

Mathematica

PARI

A155772 Primes p such that 2p^2+2p-41 is a prime.

Views

Author

Keywords

Links

Crossrefs

Programs

Magma

Mathematica

A241264 Numbers k such that 2k^2 + 2k - 41 is not a prime.

Views

Author

Keywords

Examples

Links

Crossrefs

Programs

Magma

Mathematica

cp's OEIS Frontend

A155770 Primes of form: 2*n^2+2*n-41.

Views

Author

Keywords

Examples

Links

Crossrefs

Programs

Magma

Mathematica

PARI

A155772 Primes p such that 2*p^2+2*p-41 is a prime.

Views

Author

Keywords

Links

Crossrefs

Programs

Magma

Mathematica

A241264 Numbers k such that 2*k^2 + 2*k - 41 is not a prime.

Views

Author

Keywords

Examples

Links

Crossrefs

Programs

Magma

Mathematica

A155770 Primes of form: 2n^2+2n-41.

A155772 Primes p such that 2p^2+2p-41 is a prime.

A241264 Numbers k such that 2k^2 + 2k - 41 is not a prime.