A233885 Number of (n+1) X (1+1) 0..6 arrays with every 2 X 2 subblock having the sum of the squares of the edge differences equal to 30, and no two adjacent values equal.

112, 384, 1264, 4292, 14272, 48300, 161168, 544460, 1820160, 6141480, 20556600, 69298740, 232159624, 782096432, 2621850152, 8827674288, 29608245144, 99647390252, 334350373304, 1124887110036, 3775523491352, 12698981481044

Offset

1,1

Links

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

Formula

Empirical: a(n) = 18*a(n-2) + 4*a(n-3) - 95*a(n-4) - 30*a(n-5) + 165*a(n-6) + 36*a(n-7) - 105*a(n-8) - 8*a(n-9) + 20*a(n-10).

Empirical g.f.: 4*x*(28 + 96*x - 188*x^2 - 767*x^3 + 156*x^4 + 1457*x^5 + 56*x^6 - 940*x^7 - 22*x^8 + 180*x^9) / ((1 + x)*(1 - x - 17*x^2 + 13*x^3 + 82*x^4 - 52*x^5 - 113*x^6 + 77*x^7 + 28*x^8 - 20*x^9)). - Colin Barker, Oct 12 2018

Example

Some solutions for n=5:
..3..0....0..3....2..1....1..5....5..4....5..4....0..4....3..1....5..2....1..5
..5..4....4..5....0..4....0..2....2..0....2..0....3..2....6..5....1..0....0..2
..2..0....0..2....3..2....1..5....5..4....5..1....0..4....4..1....5..2....1..5
..1..4....4..5....1..5....3..6....2..0....6..4....3..2....3..5....4..0....0..2
..2..0....6..2....4..6....1..5....5..1....2..1....1..5....0..1....5..3....4..1
..1..4....4..1....1..2....3..2....6..3....0..4....4..3....2..5....1..0....0..2

Crossrefs

Column 1 of A233892.

Sequence in context: A270759 A352585 A233892 * A235319 A203923 A235312

Adjacent sequences: A233882 A233883 A233884 * A233886 A233887 A233888

Keyword

nonn

Author

R. H. Hardin, Dec 17 2013

Status

approved