A393732 Number of free polyominoes in the {6,7} tessellation of the hyperbolic plane.

1, 1, 3, 12, 68, 483, 3946, 34472, 315571, 2980771, 28853370, 284860242, 2859192178

Offset

1,3

Links

Table of n, a(n) for n=1..13.

Formula

a(n) = P{p,q}(n) (the number of {p,q} polyominoes of size n) is equal to P{p,oo}(n) for n <= q; also P{p,q}(q+1) = P{p,oo}(q+1) + floor((p-1)/2) - floor((3+q(p-2))/2). In this case, p=6, q=7 and P{p,oo} = A004127.

Crossrefs

Cf. A393729, A393730, A393731, A393733, A004127.

Sequence in context: A393730 A296979 A393731 * A393733 A004127 A058115

Adjacent sequences: A393729 A393730 A393731 * A393733 A393734 A393735

Keyword

nonn,more

Author

John Mason, Mar 01 2026

Status

approved