A302666 Number of nX4 0..1 arrays with every element equal to 1, 2, 3 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

2, 45, 164, 934, 4267, 21949, 106793, 529984, 2617548, 12938179, 63986777, 316244862, 1563877465, 7731246308, 38227036552, 188999363652, 934471931880, 4620268994057, 22843909984025, 112946725741085, 558440468796391

Offset

1,1

Comments

Column 4 of A302670.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) +12*a(n-2) -47*a(n-3) -101*a(n-4) +45*a(n-5) +381*a(n-6) +1292*a(n-7) +42*a(n-8) -5366*a(n-9) -7123*a(n-10) +6047*a(n-11) +22989*a(n-12) +15537*a(n-13) -22434*a(n-14) -51326*a(n-15) -29224*a(n-16) +38509*a(n-17) +82591*a(n-18) +44309*a(n-19) -44268*a(n-20) -87403*a(n-21) -42575*a(n-22) +28053*a(n-23) +52051*a(n-24) +24821*a(n-25) -7290*a(n-26) -13614*a(n-27) -6288*a(n-28) +190*a(n-29) +1280*a(n-30) +312*a(n-31) +20*a(n-32) for n>35

Example

Some solutions for n=5
..0..0..1..1. .0..0..1..1. .0..0..1..1. .0..0..0..1. .0..1..1..0
..0..1..1..0. .0..0..0..0. .1..1..0..1. .1..1..1..1. .1..0..0..1
..1..0..0..1. .1..1..1..1. .1..0..0..0. .1..0..0..0. .1..1..0..0
..0..0..1..1. .0..0..0..0. .1..0..1..1. .0..1..1..0. .0..1..0..1
..0..0..1..1. .1..1..1..0. .0..1..0..0. .1..1..0..0. .0..0..1..0

Crossrefs

Cf. A302670.

Sequence in context: A281661 A019579 A302220 * A304693 A200158 A316444

Adjacent sequences: A302663 A302664 A302665 * A302667 A302668 A302669

Keyword

nonn

Author

R. H. Hardin, Apr 11 2018

Status

approved