A123824 Number of ways, counted up to symmetry, to build a contiguous building with n LEGO blocks of size 2 X 3.

1, 16, 697, 34958, 1947321, 114675898, 7026150623, 443114008903, 28575438072945, 1875587744568411

Offset

1,2

Links

Table of n, a(n) for n=1..10.

Matthias Simon, Program to compute a(1)...a(10)

Crossrefs

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

Sequence in context: A053907 A222139 A036513 * A198283 A283534 A294704

Adjacent sequences: A123821 A123822 A123823 * A123825 A123826 A123827

Keyword

nonn,hard,more

Author

Søren Eilers, Oct 29 2006

Extensions

a(9) from Matthias Simon, Aug 29 2020

a(10) from Matthias Simon, Nov 15 2020

Status

approved