A080713 Numbers not of the form p + q^2.

1, 2, 3, 4, 5, 8, 10, 13, 18, 19, 24, 25, 29, 31, 34, 37, 39, 43, 49, 53, 55, 58, 59, 61, 64, 67, 69, 73, 74, 79, 81, 85, 89, 91, 94, 95, 97, 99, 100, 103, 109, 115, 119, 121, 125, 127, 129, 130, 133, 137, 139, 142, 145, 147, 149, 151, 154, 157, 159, 163, 165, 169, 170

Offset: 1

Author

Robert G. Wilson v, Mar 05 2003

Keywords

• nonn

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Crossrefs

Complement of A081053.

Programs

Mathematica

Complement[ Table[k, {k, 1, 200}], Take[ Union[ Flatten[ Table[ Prime[i] + Prime[j]^2, {i, 1, 80}, {j, 1, 10}]]], 250]]

PARI

is(n)=if(n%2, !isprime(n-4) && isprimepower(n-2)!=2, forprime(q=3, sqrtint(n), if(isprime(n-q^2), return(0))); n!=6) \\ Charles R Greathouse IV, Oct 25 2017