OFFSET
1,2
LINKS
Peter Kagey, Illustration of T(2,2)=76
Peter Kagey and William Keehn, Counting tilings of the n X m grid, cylinder, and torus, arXiv: 2311.13072 [math.CO], 2023. See also J. Int. Seq., (2024) Vol. 27, Art. No. 24.6.1, pp. A-1, A-3.
EXAMPLE
Table begins:
n\k | 1 2 3 4 5
----+-----------------------------------------------------------
1 | 1 6 16 72 256
2 | 6 76 1056 16576 262656
3 | 16 1056 65536 4196352 268435456
4 | 72 16576 4196352 1073790976 274878431232
5 | 256 262656 268435456 274878431232 281474976710656
6 | 1056 4197376 17180000256 70368756760576 288230376688582656
MATHEMATICA
A368220[n_, m_] := 2^(n*m - 2)*(2^(n*m) + Boole[EvenQ[n*m]] + Boole[EvenQ[n]] + Boole[EvenQ[m]])
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Peter Kagey, Dec 18 2023
STATUS
approved