A182048 Numbers n such that 16n^2-2n-1 and 16n^2+2n-1 are both primes.

1, 2, 3, 5, 6, 7, 10, 13, 19, 29, 32, 36, 62, 63, 70, 75, 78, 85, 93, 96, 102, 107, 109, 119, 123, 128, 145, 158, 164, 174, 177, 190, 192, 197, 219, 241, 247, 252, 280, 284, 299, 304, 318, 335, 340, 344, 354, 361, 374, 377, 382, 385, 387, 427, 434, 439, 440

Offset

1,2

Links

Harvey P. Dale, Table of n, a(n) for n = 1..3500

Example

a(1)=1 because 16*1^2-2*1-1=13 is prime and 16*1^2+2*1-1=17 is prime.

Mathematica

Select[Range[500], PrimeQ[16 #^2 - 2 # - 1] && PrimeQ[16 #^2 + 2 # - 1] &] (* T. D. Noe, Apr 16 2012 *)
Select[Range[500], AllTrue[16#^2-1+{2#, -2#}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Jan 01 2018 *)

Crossrefs

Cf. A171748, A089637.

Sequence in context: A183071 A139826 A358374 * A028722 A030050 A018336

Adjacent sequences: A182045 A182046 A182047 * A182049 A182050 A182051

Keyword

nonn

Author

Gerasimov Sergey, Apr 08 2012

Extensions

Corrected and extended by T. D. Noe, Apr 16 2012

Status

approved