A226300 a(n) = A182107(4n).

2, 10, 114, 1322, 16428, 214660, 2897424, 40046134, 563527294, 8042361426, 116083167058, 1691193906828, 24830916046462, 366990100477712, 5454733737618820, 81475220265330158, 1222209564554562110, 18404140554678144630, 278069131820486935046, 4214088001120913287256, 64037903464421065585244

Offset

1,1

Links

Table of n, a(n) for n=1..21.

Alejandro Erickson, Frank Ruskey, Enumerating maximal tatami mat coverings of square grids with v vertical dominoes, arXiv:1304.0070 [math.CO], 2013.

Mathematica

S[0, 0] = 1; S[0, _] = 0; S[n_, k_] /; k < 0 || k > Binomial[n + 1, 2] = 0; S[n_, k_] := S[n, k] = S[n - 1, k] + S[n - 1, k - n];
b[n_] := 2 Sum[Sum[k2 = (n^2 - n)/4 - (n - i - 1) - k1; S[n - i - 2, k1]* S[i - 1, k2], {k1, 0, (n^2 - n)/4 - (n - i - 1)}] + Sum[k2 = (n^2 - n)/4; S[Floor[(n - 2)/2], k1]*S[Floor[(n - 2)/2], k2], {k1, 0, (n^2 - n)/4}], {i, 1, Floor[(n - 1)/2]}];
a[n_] := b[4n];
Table[a[n], {n, 1, 21}] (* Jean-François Alcover, Feb 23 2019 *)

Crossrefs

Cf. A182107, A226301.

Sequence in context: A168369 A363206 A317342 * A223056 A208782 A237749

Adjacent sequences: A226297 A226298 A226299 * A226301 A226302 A226303

Keyword

nonn

Author

N. J. A. Sloane, Jun 06 2013

Status

approved