A251232 Number of (n+1) X (4+1) 0..3 arrays with every 2 X 2 subblock summing to 6 and no 2 X 2 subblock having exactly two nonzero entries.

966, 1870, 3886, 8686, 20490, 50570, 129378, 340782, 918878, 2525262, 7049658, 19942026, 57058610, 164910430, 480976574, 1414571198, 4192696714, 12517386890, 37626434786, 113828691374, 346430157502, 1060262602062, 3261932440186

Offset

1,1

Comments

Column 4 of A251236.

Links

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

Formula

Empirical: a(n) = 13*a(n-1) -63*a(n-2) +122*a(n-3) +13*a(n-4) -371*a(n-5) +317*a(n-6) +308*a(n-7) -370*a(n-8) -144*a(n-9) +128*a(n-10) +48*a(n-11).

Example

Some solutions for n=4:
..0..2..0..3..0....1..1..0..2..2....3..1..3..1..1....0..1..0..1..1
..1..3..1..2..1....2..2..3..1..1....0..2..0..2..2....2..3..2..3..1
..2..0..2..1..2....1..1..0..2..2....3..1..3..1..1....0..1..0..1..1
..3..1..3..0..3....1..3..2..2..0....1..1..1..1..3....2..3..2..3..1
..1..1..1..2..1....2..0..1..1..3....3..1..3..1..1....1..0..1..0..2

Crossrefs

Cf. A251236.

Sequence in context: A345802 A014363 A260291 * A202049 A246477 A064258

Adjacent sequences: A251229 A251230 A251231 * A251233 A251234 A251235

Keyword

nonn

Author

R. H. Hardin, Nov 30 2014

Status

approved