A302324 Number of 3 X n 0..1 arrays with every element equal to 0, 1, 2 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 25, 65, 177, 519, 1528, 4509, 13329, 39609, 117981, 351994, 1051660, 3146513, 9424435, 28252647, 84757174, 254424013, 764109856, 2295781145, 6900025071, 20743913296, 62377653458, 187606559148, 564330015524, 1697745322295, 5108065042362, 15370102161553, 46251622171599

Offset

1,1

Comments

Row 3 of A302322.

Links

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

Formula

Empirical: a(n) = 5*a(n-1) -4*a(n-2) -6*a(n-3) +a(n-4) -15*a(n-5) +25*a(n-6) +37*a(n-7) +8*a(n-8) -27*a(n-9) -57*a(n-10) -49*a(n-11) +51*a(n-12) +44*a(n-13) -12*a(n-14) for n>15.

Example

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

Crossrefs

Cf. A302322.

Sequence in context: A368245 A212893 A376483 * A303017 A281339 A298282

Adjacent sequences: A302321 A302322 A302323 * A302325 A302326 A302327

Keyword

nonn

Author

R. H. Hardin, Apr 05 2018

Status

approved