A109807 Numbers n such that n^2 + 1 is a Chen prime.

1, 2, 4, 6, 10, 14, 16, 20, 24, 26, 36, 40, 56, 66, 74, 94, 116, 120, 130, 134, 146, 160, 170, 176, 204, 230, 250, 256, 260, 284, 314, 326, 340, 350, 386, 406, 430, 440, 444, 464, 466, 470, 490, 496, 536, 556, 570, 584, 634, 646, 654, 680, 686, 700, 704, 714

Offset: 1

Author

Jason Earls, Aug 16 2005

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Subsequence of A005574.

Cf. A005574, A109611.

Programs

Mathematica

Select[Range[800],PrimeQ[#^2+1]&&PrimeOmega[#^2+3]<3&] (* Harvey P. Dale, May 07 2015 *)

PARI

is(n)=isprime(n^2+1) && bigomega(n^2+3)<3 \\ Charles R Greathouse IV, Aug 19 2015