A302369 Number of 3Xn 0..1 arrays with every element equal to 0, 2, 3 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 2, 31, 20, 154, 284, 1109, 3472, 12763, 48721, 190256, 770983, 3134572, 12931018, 53433431, 221779682, 921445395, 3833216521, 15953742306, 66423173327, 276603513242, 1151978426752, 4797997758989, 19984422198978, 83240190604547

Offset

1,1

Comments

Row 3 of A302367.

Links

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

Formula

Empirical: a(n) = 6*a(n-1) +a(n-2) -47*a(n-3) +13*a(n-4) +158*a(n-5) -30*a(n-6) -242*a(n-7) -62*a(n-8) +224*a(n-9) +26*a(n-10) +11*a(n-11) +64*a(n-12) -114*a(n-13) -27*a(n-14) +26*a(n-15) -6*a(n-16) for n>18

Example

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

Crossrefs

Cf. A302367.

Sequence in context: A353750 A093991 A030447 * A317899 A076936 A344536

Adjacent sequences: A302366 A302367 A302368 * A302370 A302371 A302372

Keyword

nonn

Author

R. H. Hardin, Apr 06 2018

Status

approved