A123790 Number of ways to build a contiguous building with n LEGO blocks of size 1 X 5 on top of a fixed block of the same size.

34, 1516, 93664, 6366476, 468438942, 36108392112, 2882260782674

Offset: 1

Author

Søren Eilers, Oct 29 2006

Keywords

• nonn
• hard

Comments

The base block is not counted among the n and must be the only block in the bottom layer of the building.

Crossrefs

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