

A281028


Number of n X 2 0..1 arrays with no element equal to more than three of its kingmove neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.


1



0, 0, 2, 12, 58, 252, 1048, 4204, 16454, 63236, 239622, 897792, 3332864, 12277952, 44938282, 163566412, 592492026, 2137194788, 7680594760, 27511516436, 98254943022, 349979793492, 1243627373550, 4409519905928, 15603737422416
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OFFSET

1,3


LINKS

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


FORMULA

Empirical: a(n) = 6*a(n1)  7*a(n2)  2*a(n3)  17*a(n4) + 24*a(n6) + 16*a(n7) + 12*a(n8)  16*a(n9)  16*a(n10).
Empirical g.f.: 2*x^3*(1  2*x^3)^2 / (1  3*x  x^2  2*x^3 + 2*x^4 + 4*x^5)^2.  Colin Barker, Feb 15 2019


EXAMPLE

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


CROSSREFS

Column 2 of A281034.
Sequence in context: A094780 A268594 A100103 * A054145 A285364 A282435
Adjacent sequences: A281025 A281026 A281027 * A281029 A281030 A281031


KEYWORD

nonn


AUTHOR

R. H. Hardin, Jan 13 2017


STATUS

approved



