A005870 Numbers represented by hexagonal close-packing.

0, 3, 6, 8, 9, 11, 12, 15, 17, 18, 19, 20, 21, 22, 25, 27, 29, 30, 31, 32, 33, 34, 35, 36, 37, 39, 41, 43, 44, 45, 46, 47, 48, 49, 51, 53, 54, 55, 56, 57, 59, 61, 63, 65, 66, 67, 68, 69, 70, 71, 72, 75

Offset: 1

Author

N. J. A. Sloane

Keywords

• easy
• nonn

Comments

Numbers n such that A004012(n) != 0. - Sean A. Irvine, Sep 23 2016

References

• J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 114.
• S. E. Thiel, Generating Functions for Fibonomial Coefficients and Fibonacci Products, http://stuartthiel.homestead.com/files/fibonacci/THIEL_fibonomial_coefficients_rev110612.pdf [Broken link?]
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A004012.