A280676 Number of 4Xn 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.

14, 612, 12484, 310365, 7533245, 183331502, 4460317695, 108520231044, 2640298250694, 64238619127022, 1562929767205929, 38026186043293995, 925179685380850290, 22509684536321285656, 547662154172647585113

Offset: 1

Author

R. H. Hardin, Jan 07 2017

Keywords

• nonn

Comments

Row 4 of A280673.

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n = 1..210
• R. H. Hardin, Empirical recurrence of order 73

Crossrefs

Cf. A280673.

Formula

Empirical recurrence of order 73 (see link above)