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A221110 Number of n X 4 arrays of occupancy after each element moves to some horizontal or antidiagonal neighbor, without 2-loops. 1
0, 7, 178, 3706, 73267, 1424745, 27551817, 531785885, 10257442136, 197807790635, 3814292012327, 73548334004184, 1418168141939766, 27345207646288006, 527271440369708686, 10166866164855156013, 196037839679146009768 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A221114.

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..26

FORMULA

Empirical: a(n) = 29*a(n-1) - 210*a(n-2) + 451*a(n-3) - 288*a(n-4) + 20*a(n-5) - a(n-6).

Empirical g.f.: x^2*(1 - 2*x)*(7 - 11*x - 8*x^2) / ((1 - x)*(1 - 28*x + 182*x^2 - 269*x^3 + 19*x^4 - x^5)). - Colin Barker, Aug 03 2018

EXAMPLE

Some solutions for n=3:

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

..0..1..1..0....1..2..3..1....0..2..2..1....0..3..2..0....0..2..3..1

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

CROSSREFS

Cf. A221114.

Sequence in context: A009708 A231490 A231489 * A142256 A226427 A226550

Adjacent sequences:  A221107 A221108 A221109 * A221111 A221112 A221113

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 02 2013

STATUS

approved

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Last modified September 26 03:19 EDT 2021. Contains 347664 sequences. (Running on oeis4.)