A123806 Number of ways to build a contiguous building with n LEGO blocks of size 1 X 7 on top of a fixed block of the same size.

62, 5188, 603490, 77670923, 10795814511, 1572624052679

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.