A265929 Number of 1 X n 0..4 arrays with the absolute differences of each element with its with horizontal and antidiagonal neighbors unique.

5, 25, 92, 340, 1252, 4616, 17012, 62696, 231044, 851496, 3138100, 11564952, 42620580, 157071768, 578865076, 2133318088, 7862009732, 28974227016, 106780086132, 393521606584, 1450263256356, 5344722135352, 19697152196980

Offset: 1

Author

R. H. Hardin, Dec 18 2015

Keywords

• nonn

Comments

Row 1 of A265928.

Examples

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

Links

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

Crossrefs

Cf. A265928.

Formula

Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + 10*a(n-3) + 27*a(n-4) - 13*a(n-5) + 28*a(n-6) - 20*a(n-7) - 96*a(n-8) for n>9.

Empirical g.f.: x*(1 + x)*(5 + 5*x + 22*x^2 + 42*x^3 - 11*x^4 + 21*x^5 - 52*x^6 - 160*x^7) / (1 - 3*x + 2*x^2 - 10*x^3 - 27*x^4 + 13*x^5 - 28*x^6 + 20*x^7 + 96*x^8). - Colin Barker, Mar 21 2018