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A268805 Number of nX4 0..2 arrays with some element plus some horizontally, vertically or antidiagonally adjacent neighbor totalling two not more than once. 1
60, 290, 1202, 5848, 28452, 135912, 640926, 2990786, 13835892, 63544542, 290056316, 1317009868, 5952527788, 26795651036, 120193389832, 537427198324, 2396207992178, 10656560102448, 47282655935580, 209348341875062 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A268809.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) +19*a(n-2) +10*a(n-3) -122*a(n-4) -320*a(n-5) -295*a(n-6) +8*a(n-7) +176*a(n-8) +20*a(n-9) -98*a(n-10) -6*a(n-11) +43*a(n-12) -6*a(n-13) -11*a(n-14) +6*a(n-15) -a(n-16) for n>19

EXAMPLE

Some solutions for n=4

..2..2..2..2. .2..2..2..1. .1..2..1..2. .2..2..1..2. .0..2..2..2

..2..1..2..1. .1..2..1..2. .1..2..2..2. .1..2..1..2. .1..2..1..2

..1..2..2..2. .2..2..2..2. .2..2..2..1. .2..2..2..2. .2..2..2..2

..2..2..1..2. .1..2..2..1. .1..2..2..2. .1..2..1..2. .1..2..2..2

CROSSREFS

Cf. A268809.

Sequence in context: A100151 A338109 A179811 * A146750 A298045 A063497

Adjacent sequences:  A268802 A268803 A268804 * A268806 A268807 A268808

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 13 2016

STATUS

approved

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Last modified August 8 12:30 EDT 2022. Contains 356009 sequences. (Running on oeis4.)