A243889 Primes of the form 2*n^2+30*n+13.

661, 1201, 2281, 2713, 3181, 4801, 5413, 8221, 9013, 12541, 13513, 17761, 18913, 20101, 32413, 33961, 38821, 51421, 72481, 91921, 94513, 108013, 110821, 134581, 137713, 153913, 167521, 211801, 223681, 265621, 274441, 335281, 345181, 365413, 370561, 440761, 560641

Offset: 1

Author

Vincenzo Librandi, Jun 16 2014

Keywords

• nonn
• easy

Comments

Subsequence of A142104.

Conjecture: except 2281, 2^a(n)-1 is not prime; in other words, these primes are included in A054723.

2*a(n) + 199 is a square. - Vincenzo Librandi, Apr 10 2015

Links

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

Crossrefs

Cf. A142104.

Cf. similar sequences listed in A243888.

Programs

Magma

[a: n in [1..800] | IsPrime(a) where a is 2*n^2+30*n+13];

Mathematica

Select[Table[2 n^2 + 30 n + 13, {n, 1000}], PrimeQ]