A304672 - OEIS

A304672

Number of nX4 0..1 arrays with every element unequal to 0, 2, 3, 5 or 6 king-move adjacent elements, with upper left element zero.

1, 13, 23, 56, 199, 598, 1950, 6588, 21871, 72947, 246313, 831539, 2800595, 9456853, 31947922, 107896991, 364471611, 1231447079, 4160781508, 14058449969, 47502997786, 160513512708, 542381014412, 1832740869231, 6192990940151

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Column 4 of A304676.

LINKS

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

R. H. Hardin, Empirical recurrence of order 70

FORMULA

Empirical recurrence of order 70 (see link above)

EXAMPLE

Some solutions for n=5

..0..1..1..0. .0..1..0..1. .0..0..1..0. .0..1..1..0. .0..0..0..1

..0..1..0..1. .1..0..1..0. .1..1..0..1. .0..1..0..1. .1..1..0..0

..0..1..0..1. .1..1..0..0. .1..1..1..0. .0..0..1..1. .0..1..1..1

..0..0..1..0. .1..0..1..0. .1..1..0..1. .0..1..0..1. .1..1..0..1

..1..0..0..1. .0..1..0..1. .0..0..1..0. .1..0..0..1. .0..0..0..1

CROSSREFS

Cf. A304676.

Sequence in context: A154863 A194156 A139863 * A316119 A046862 A155093

Adjacent sequences: A304669 A304670 A304671 * A304673 A304674 A304675

KEYWORD

nonn

AUTHOR

R. H. Hardin, May 16 2018

STATUS

approved