A303514 Number of 3Xn 0..1 arrays with every element equal to 0, 1, 2, 4, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 25, 78, 230, 801, 2764, 9367, 31703, 107876, 366903, 1247178, 4239444, 14413593, 49004114, 166604979, 566429535, 1925785826, 6547430725, 22260469676, 75682984684, 257313518769, 874837061986, 2974348729093, 10112457309015

Offset

1,1

Comments

Row 3 of A303513.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -7*a(n-2) -9*a(n-3) +6*a(n-4) -3*a(n-5) +48*a(n-6) +22*a(n-7) -35*a(n-8) -104*a(n-9) -47*a(n-10) +77*a(n-11) +110*a(n-12) -13*a(n-13) -56*a(n-14) +12*a(n-15) for n>16

Example

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

Crossrefs

Cf. A303513.

Sequence in context: A125309 A273361 A266126 * A041991 A027764 A095669

Adjacent sequences: A303511 A303512 A303513 * A303515 A303516 A303517

Keyword

nonn

Author

R. H. Hardin, Apr 25 2018

Status

approved