A230834 Loeschian semiprimes: semiprimes of the form x^2 + x*y + y^2.

4, 9, 21, 25, 39, 49, 57, 91, 93, 111, 121, 129, 133, 169, 183, 201, 217, 219, 237, 247, 259, 289, 291, 301, 309, 327, 361, 381, 403, 417, 427, 453, 469, 471, 481, 489, 511, 529, 543, 553, 559, 579, 589, 597, 633, 669, 679, 687, 703, 721, 723, 763, 793, 813, 817, 831, 841, 849, 871

Offset

1,1

Comments

Intersection of A001358 and A003136.

Loeschian primes equals generalized cuban primes (A007645).

Links

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

Prog

(PARI) list(lim)=my(v=List()); forprime(p=2, lim\2, forprime(q=2, min(lim\p, p), if((p%3<2 && q%3<2) || p==q, listput(v, p*q)))); vecsort(Vec(v)) \\ Charles R Greathouse IV, Oct 31 2013

Crossrefs

Sequence in context: A228642 A334261 A290434 * A120535 A146948 A033944

Adjacent sequences: A230831 A230832 A230833 * A230835 A230836 A230837

Keyword

nonn

Author

Irina Gerasimova, Oct 31 2013

Status

approved