A296381 Number of nX3 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 2 neighboring 1s.

4, 28, 127, 641, 3237, 16248, 81661, 410199, 2061212, 10356724, 52036349, 261457677, 1313693921, 6600648217, 33164941657, 166637153693, 837267911142, 4206850248548, 21137307140110, 106204340013363, 533623405850063

Offset

1,1

Comments

Column 3 of A296386.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -2*a(n-2) +14*a(n-3) -20*a(n-4) +24*a(n-5) -52*a(n-6) +83*a(n-7) -82*a(n-8) +43*a(n-9) -5*a(n-10) -4*a(n-11) -9*a(n-12) +19*a(n-13) -15*a(n-14) +6*a(n-15) -a(n-16)

Example

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

Crossrefs

Cf. A296386.

Sequence in context: A131459 A231581 A223115 * A240434 A270275 A296638

Adjacent sequences: A296378 A296379 A296380 * A296382 A296383 A296384

Keyword

nonn

Author

R. H. Hardin, Dec 11 2017

Status

approved