A264648 Number of (n+1)X(n+1) arrays of permutations of 0..(n+1)^2-1 with each element having directed index change 1,1 2,2 -1,0 or 0,-1.

0, 2, 4, 112, 6656, 580796, 159104356, 100746278612, 155176061188544, 611605792148765530

Offset

1,2

Comments

Diagonal of A264655.

Links

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

Example

Some solutions for n=4
..5..2..3..4..9....5..6..3..4..9....5..6..3..4..9....5..2..3..4..9
..6..0..1.13.14...10..7.12..2.14...10..0..8..2.14....6..0..8.13.14
.15.16.17..7..8...15.16..0..1..8...11.16.13..1.19...15.12.17..1.19
.20.10.18.19.24...20.17.11.19.13...20.17.22.12..7...20.10.11.23..7
.21.22.23.11.12...21.22.23.24.18...21.15.23.24.18...21.22.16.24.18

Crossrefs

Cf. A264655.

Sequence in context: A018449 A156506 A018455 * A289343 A018463 A132497

Adjacent sequences: A264645 A264646 A264647 * A264649 A264650 A264651

Keyword

nonn

Author

R. H. Hardin, Nov 20 2015

Status

approved