A280675 Number of 3Xn 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

5, 82, 858, 10205, 119440, 1401470, 16438612, 192831783, 2261964301, 26533504354, 311245493388, 3650998431229, 42827250423319, 502375841919309, 5893011645334528, 69126704336253119, 810875921978239834

Offset: 1

Author

R. H. Hardin, Jan 07 2017

Keywords

• nonn

Comments

Row 3 of A280673.

Examples

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

Links

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

Crossrefs

Cf. A280673.

Formula

Empirical: a(n) = 11*a(n-1) +23*a(n-2) -160*a(n-3) -172*a(n-4) +690*a(n-5) +601*a(n-6) -513*a(n-7) -1314*a(n-8) -1903*a(n-9) +1720*a(n-10) +2445*a(n-11) -549*a(n-12) -998*a(n-13) +40*a(n-14) +136*a(n-15) +96*a(n-16) -32*a(n-17) -64*a(n-18) for n>20