A251235 Number of (n+1) X (7+1) 0..3 arrays with every 2 X 2 subblock summing to 6 and no 2 X 2 subblock having exactly two nonzero entries.

27714, 42850, 71322, 129378, 250622, 514950, 1112526, 2511890, 5892002, 14279706, 35575142, 90692606, 235679686, 622362410, 1666024058, 4512772642, 12352459294, 34135460774, 95175625390, 267630015058, 758790404898, 2168797835866

Offset

1,1

Comments

Column 7 of A251236.

Links

R. H. Hardin, Table of n, a(n) for n = 1..112

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:
..2..0..2..2..2..1..1..1....2..2..2..1..1..2..2..0....2..0..3..1..3..1..2..1
..1..3..1..1..1..2..2..2....1..1..1..2..2..1..1..3....2..2..1..1..1..1..2..1
..2..0..2..2..2..1..1..1....2..2..2..1..1..2..2..0....1..1..2..2..2..2..1..2
..2..2..2..0..2..1..3..1....1..1..1..2..2..1..1..3....3..1..2..0..2..0..3..0
..1..1..1..3..1..2..0..2....2..2..2..1..1..2..2..0....2..0..3..1..3..1..2..1

Crossrefs

Cf. A251236.

Sequence in context: A339257 A202589 A079321 * A023198 A230608 A204831

Adjacent sequences: A251232 A251233 A251234 * A251236 A251237 A251238

Keyword

nonn

Author

R. H. Hardin, Nov 30 2014

Status

approved