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A295209 Number of n X 4 0..1 arrays with each 1 horizontally or vertically adjacent to 2 or 3 1's. 1
1, 7, 27, 147, 916, 4938, 27208, 152236, 848992, 4746938, 26555583, 148468255, 830063597, 4640855585, 25946470239, 145065530889, 811058197498, 4534601269690, 25352811924120, 141746752099136, 792501412285360 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 4 of A295213.
LINKS
FORMULA
Empirical: a(n) = 8*a(n-1) -17*a(n-2) +27*a(n-3) -66*a(n-4) +182*a(n-5) -188*a(n-6) -199*a(n-7) -22*a(n-8) +185*a(n-9) +385*a(n-10) +169*a(n-11) +49*a(n-12) +408*a(n-13) +516*a(n-14) -492*a(n-15) -1779*a(n-16) -408*a(n-17) +326*a(n-18) -331*a(n-19) +505*a(n-20) -310*a(n-21) +217*a(n-22) -111*a(n-23) +4*a(n-24) -16*a(n-25) +4*a(n-26) +4*a(n-27) -a(n-28).
EXAMPLE
Some solutions for n=7
..0..0..1..1. .1..1..1..1. .1..1..1..1. .1..1..0..0. .0..1..1..1
..0..0..1..1. .1..0..1..1. .1..0..1..1. .1..1..1..0. .1..1..1..1
..0..0..1..1. .1..1..1..1. .1..1..0..0. .1..0..1..0. .1..0..0..0
..0..0..1..1. .0..1..0..0. .0..1..1..0. .1..0..1..0. .1..1..1..0
..1..1..1..1. .0..1..1..0. .0..0..1..0. .1..0..1..0. .1..1..1..0
..1..1..0..1. .0..1..1..0. .0..1..1..0. .1..1..1..0. .0..0..1..1
..0..1..1..1. .0..0..0..0. .0..1..1..0. .1..1..0..0. .0..0..1..1
CROSSREFS
Cf. A295213.
Sequence in context: A283538 A214459 A179597 * A151496 A202519 A192250
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 17 2017
STATUS
approved

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Last modified June 12 23:46 EDT 2024. Contains 373362 sequences. (Running on oeis4.)