A123770 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 3.

1, 8, 152, 3594, 96105, 2734356, 81126946, 2480378897, 77597683206, 2472038270424

Offset: 1

Author

Søren Eilers, Oct 29 2006

Keywords

• nonn
• hard
• more

Links

• S. Eilers, The LEGO counting problem, Amer. Math. Monthly, 123 (May 2016), 415-426.
• Index entry for sequences related to LEGO blocks

Crossrefs

Cf. A112389, A123762-A123827, A123829-A123849.