A123796 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1 X 6 which is flat, i.e., with all blocks in parallel position.

1, 6, 79, 1138, 18057, 296884, 5022086, 86581805, 1515222912

Offset: 1

Author

Søren Eilers, Oct 29 2006

Keywords

• nonn
• hard

Crossrefs

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