A263507 Number of (1+1)X(n+1) arrays of permutations of 0..n*2+1 filled by rows with each element moved a city block distance of 0 1 or 2, and rows and columns in increasing lexicographic order.

8, 48, 204, 770, 2687, 8559, 25383, 71498, 193691, 508996, 1306369, 3291584, 8173381, 20060419, 48777993, 117717414, 282365804, 673959638, 1602152316, 3796140809, 8970338435, 21150183227, 49777148466, 116976012851, 274555052038

Offset

1,1

Comments

Row 1 of A263506.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 6*a(n-1) -12*a(n-2) +9*a(n-3) -4*a(n-4) +2*a(n-5) +10*a(n-6) -12*a(n-7) -a(n-10) +4*a(n-11) -a(n-13)

Example

Some solutions for n=4
..0..1..2..4..9....1..2..4..7..8....0..2..4..7..8....0..1..2..8..9
..5..8..3..6..7....5..0..3..6..9....5..1..6..9..3....6..7..5..4..3

Crossrefs

Cf. A263506.

Sequence in context: A187174 A128796 A093199 * A261975 A087914 A271061

Adjacent sequences: A263504 A263505 A263506 * A263508 A263509 A263510

Keyword

nonn

Author

R. H. Hardin, Oct 19 2015

Status

approved