OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
Vaclav Kotesovec, G.f. and the recurrence (of order 315)
Wikipedia, Pentomino
FORMULA
a(n) ~ c * d^n, where d = 2.6877447474867836174937272605197376719631593933016281800670782370745298422..., c = 0.3236150736074998563483897952085529328299218049725560430481595704054051228... (1/d is the root of the denominator, see g.f.). - Vaclav Kotesovec, May 19 2015
EXAMPLE
a(4) = 13:
._______. ._______. ._______.
| | | | | | ._| ._| | | ._| |
| | | | | | |_. | | | | | | |
| | | | | | | |_| | | | | | |
| | | | | |_| ._| | | |_| | |
|_|_|_|_| (1) |___|___| (2) |_|___|_| (2)
._______. ._______. ._______.
| ._| | | | ._| ._| | ._|_. |
| | | | | | | | | | | | | | |
| | | | | | | | | | | | | | |
|_| | | | |_| |_| | |_| | |_|
|___|_|_| (4) |___|___| (2) |___|___| (2) .
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Dec 03 2014
STATUS
approved