A267975 Number of 1 X n 0..3 arrays with every repeated value in every row greater than or equal to, and in every column greater than, the previous repeated value.

4, 16, 64, 250, 964, 3674, 13868, 51917, 192980, 712868, 2618876, 9573915, 34845780, 126322410, 456285828, 1642687662, 5895922368, 21102304252, 75332038300, 268275675007, 953247943192, 3380004168904, 11961143709736, 42249741430325

Offset

1,1

Comments

Row 1 of A267974.

Links

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

Formula

Empirical: a(n) = 12*a(n-1) - 50*a(n-2) + 72*a(n-3) + 21*a(n-4) - 72*a(n-5) - 50*a(n-6) - 12*a(n-7) -a(n-8).

Empirical g.f.: x*(4 - 32*x + 72*x^2 - 6*x^3 - 72*x^4 - 50*x^5 - 12*x^6 - x^7) / (1 - 3*x - x^2)^4. - Colin Barker, Feb 26 2018

Example

Some solutions for n=8:
..0..0..3..1..1..2..2..1....3..2..0..1..3..2..1..1....2..1..2..2..0..1..2..1

Crossrefs

Cf. A267974.

Sequence in context: A006811 A269685 A269614 * A269489 A259898 A307945

Adjacent sequences: A267972 A267973 A267974 * A267976 A267977 A267978

Keyword

nonn

Author

R. H. Hardin, Jan 23 2016

Status

approved