A301661 - OEIS

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A301661

Number of nX7 0..1 arrays with every element equal to 0, 1 or 4 horizontally or vertically adjacent elements, with upper left element zero.

21, 22, 46, 89, 223, 696, 2335, 8380, 31001, 116558, 442314, 1686894, 6453062, 24725894, 94832665, 363935417, 1397133323, 5364622673, 20601302508, 79119265773, 303870780015, 1167097983033, 4482628695760, 17217197273712

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

OFFSET

1,1

COMMENTS

Column 7 of A301662.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) -5*a(n-2) +14*a(n-3) -44*a(n-4) -2*a(n-5) -63*a(n-6) +117*a(n-7) +133*a(n-8) +386*a(n-9) +126*a(n-10) -575*a(n-11) -1064*a(n-12) -876*a(n-13) +203*a(n-14) +1305*a(n-15) +1617*a(n-16) +681*a(n-17) -882*a(n-18) -1502*a(n-19) -879*a(n-20) +297*a(n-21) +793*a(n-22) +486*a(n-23) +6*a(n-24) -191*a(n-25) -108*a(n-26) -14*a(n-27) +20*a(n-28) +12*a(n-29) +4*a(n-30) +a(n-31)

EXAMPLE

Some solutions for n=5

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

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

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

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

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

CROSSREFS

Cf. A301662.

Sequence in context: A041884 A041882 A286762 * A281364 A041900 A041902

Adjacent sequences: A301658 A301659 A301660 * A301662 A301663 A301664

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 25 2018

STATUS

approved