A123786 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 1x5.

1, 18, 952, 60878, 4319328, 325354277, 25539764546, 2066227060325

Offset

1,2

Links

Table of n, a(n) for n=1..8.

Crossrefs

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

Sequence in context: A242446 A160013 A356687 * A333089 A129009 A042409

Adjacent sequences: A123783 A123784 A123785 * A123787 A123788 A123789

Keyword

nonn,hard

Author

Søren Eilers, Oct 29 2006

Status

approved