A266132 Number of 2Xn integer arrays with each element equal to the number of horizontal, diagonal and antidiagonal neighbors exactly one smaller than itself.

1, 9, 25, 49, 149, 625, 2141, 5433, 17269, 65249, 214877, 600025, 1934485, 6961153, 22488637, 66171721, 214994149, 746222545, 2392193165, 7273608601, 23705004725, 80233190113, 256613628509, 797094034921, 2598493640773, 8647653815601

Offset

1,2

Comments

Row 2 of A266131.

Links

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

Formula

Empirical: a(n) = a(n-1) +8*a(n-3) +80*a(n-4) -40*a(n-5) -52*a(n-6) -112*a(n-7) -1204*a(n-8) +292*a(n-9) +64*a(n-10) -880*a(n-11) +4016*a(n-12) -2112*a(n-13) -1152*a(n-14) +1024*a(n-15) -4608*a(n-16) +4608*a(n-17)

Example

Some solutions for n=4
..1..2..0..1....1..1..1..2....1..1..1..1....1..1..0..1....0..2..0..1
..0..0..1..1....0..0..1..2....1..0..0..1....1..0..2..0....1..0..1..1

Crossrefs

Cf. A266131.

Sequence in context: A245694 A045972 A297596 * A112629 A225322 A031162

Adjacent sequences: A266129 A266130 A266131 * A266133 A266134 A266135

Keyword

nonn

Author

R. H. Hardin, Dec 21 2015

Status

approved