A183467 - OEIS

A183467

Number of n X 2 binary arrays with every element equal to either the sum mod 2 of its vertical neighbors or the sum mod 2 of its horizontal neighbors.

2, 6, 12, 28, 68, 156, 368, 872, 2048, 4832, 11408, 26896, 63456, 149728, 353216, 833344, 1966144, 4638656, 10944000, 25820288, 60917760, 143723520, 339087616, 800010496, 1887468032, 4453111296, 10506243072, 24787422208, 58481067008

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OFFSET

1,1

COMMENTS

Column 2 of A183474.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..200

FORMULA

Empirical: a(n) = 2*a(n-1) + 4*a(n-3) - 4*a(n-4) - 4*a(n-6).

Empirical g.f.: 2*x*(1 + x - 2*x^3 - 2*x^4 - 2*x^5) / ((1 - 2*x^3)*(1 - 2*x - 2*x^3)). - Colin Barker, Mar 29 2018

EXAMPLE

Some solutions for 4 X 2: