A301395 Number of nX3 0..1 arrays with every element equal to 2, 3, 4, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

0, 2, 3, 13, 44, 156, 554, 1963, 6964, 24699, 87617, 310815, 1102602, 3911438, 13875683, 49223528, 174618908, 619455124, 2197497772, 7795555028, 27654489341, 98103442446, 348018917203, 1234586307769, 4379656611234, 15536695906316

Offset

1,2

Comments

Column 3 of A301400.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +2*a(n-2) -a(n-3) +3*a(n-4) +3*a(n-5) -8*a(n-6) -13*a(n-7) -13*a(n-8) -7*a(n-9) -8*a(n-10) -7*a(n-11) -a(n-12) +a(n-13) -2*a(n-14) +a(n-15)

Example

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

Crossrefs

Cf. A301400.

Sequence in context: A235626 A164133 A226938 * A206776 A275556 A214888

Adjacent sequences: A301392 A301393 A301394 * A301396 A301397 A301398

Keyword

nonn

Author

R. H. Hardin, Mar 20 2018

Status

approved