A038587 Sizes of successive clusters in hexagonal lattice A_2 centered at deep hole.

3, 6, 12, 12, 18, 21, 27, 27, 30, 36, 42, 42, 48, 48, 54, 54, 63, 69, 69, 69, 75, 78, 84, 84, 90, 96, 102, 102, 102, 102, 114, 114, 120, 123, 129, 129, 135, 141, 141, 141, 144, 150, 156, 156, 168, 168, 174, 174, 174

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Comments

The hexagonal lattice is the familiar 2-dimensional lattice in which each point has 6 neighbors. This is sometimes called the triangular lattice.

Links

• G. Nebe and N. J. A. Sloane, Home page for hexagonal (or triangular) lattice A2

Crossrefs

Partial sums of A005882.

Cf. A038588.

Programs

Mathematica

CoefficientList[3 QPochhammer[q^3]^3 / QPochhammer[q] + O[q]^50, q] // Accumulate (* Jean-François Alcover, Jul 05 2019 *)