A112770 Products of pairs of terms from A003627.

4, 10, 22, 25, 34, 46, 55, 58, 82, 85, 94, 106, 115, 118, 121, 142, 145, 166, 178, 187, 202, 205, 214, 226, 235, 253, 262, 265, 274, 289, 295, 298, 319, 334, 346, 355, 358, 382, 391, 394, 415, 445, 451, 454, 466, 478, 493, 502, 505, 514, 517, 526, 529, 535

Offset

1,1

Comments

It would be incorrect to call these Eisenstein semiprimes. For the Eisenstein primes see A055664. - N. J. A. Sloane, Feb 06 2008. For

References

Conway, J. H. and Guy, R. K., The Book of Numbers. New York: Springer-Verlag, pp. 220-223, 1996.

Wagon, S. "Eisenstein Primes." Section 9.8 in Mathematica in Action. New York: W. H. Freeman, pp. 319-323, 1991.

Links

Table of n, a(n) for n=1..54.

Eric Weisstein's World of Mathematics, Eisenstein Integer.

Eric Weisstein's World of Mathematics, Eisenstein Prime.

Eric Weisstein's World of Mathematics, Semiprime.

Formula

{a(n)} = {p*q: p and q both elements of A007645} = {p*q: p and q both of form 3*m^2 * n^2 for integers m, n}.

Crossrefs

Cf. A001358, A003627.

Sequence in context: A227803 A109885 A054211 * A338910 A217514 A235142

Adjacent sequences: A112767 A112768 A112769 * A112771 A112772 A112773

Keyword

easy,nonn

Author

Jonathan Vos Post and Ray Chandler, Oct 15 2005

Extensions

Definition corrected by N. J. A. Sloane, Feb 06 2008

Status

approved