A103686 Even semiprimes of the form p^2 + q^2, where p and q are primes.

34, 58, 74, 146, 178, 194, 218, 298, 314, 386, 458, 482, 538, 554, 698, 818, 866, 1082, 1202, 1322, 1418, 1538, 1658, 1706, 1858, 1874, 2018, 2042, 2138, 2218, 2234, 2258, 2498, 2642, 2818, 2858, 2978, 3098, 3218, 3338, 3506, 3578, 3602

Offset

1,1

Links

Table of n, a(n) for n=1..43.

Example

p^2 + q^2 = 2r with r equal [(p+q)/2]^2 + [q -(p+q)/2]^2.

Mathematica

Select[Union[Total[#^2]&/@Tuples[Prime[Range[20]], 2]], EvenQ[#] && PrimeOmega[#] == 2&] (* Harvey P. Dale, Jun 18 2015 *)

Crossrefs

Cf. A103558.

Sequence in context: A176687 A224896 A103558 * A211715 A108610 A261314

Adjacent sequences: A103683 A103684 A103685 * A103687 A103688 A103689

Keyword

nonn

Author

Giovanni Teofilatto, Mar 27 2005; corrected Mar 29 2005

Status

approved