A375170 Primes that can be expressed as the sum of a prime and twice a positive square.

5, 7, 11, 13, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307

Offset: 1

Author

Stefano Spezia, Aug 16 2024

Keywords

• nonn

Examples

			23 is a term since it equals 5 + 2*3^2.
		

References

• Albert H. Beiler, Recreations in the theory of numbers, New York, Dover, (2nd ed.) 1966. See p. 226.

Crossrefs

Complement of A042978 in A000040.

Cf. A001105.

Programs

Mathematica

a={}; For[i=1, i<=63, i++,For[j=1, (d=Prime[i]-2j^2)>0, j++,If[PrimeQ[d]&&!MemberQ[a,Prime[i]],AppendTo[a,Prime[i]]]]]; a