A302267 Number of 3 X n 0..1 arrays with every element equal to 0, 1, 2 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

4, 32, 153, 772, 3818, 19191, 96004, 481261, 2411557, 12086268, 60572976, 303579352, 1521476119, 7625336613, 38216661796, 191534345225, 959932146275, 4810989844333, 24111728148027, 120843206657400, 605642220203867

Offset

1,1

Comments

Row 3 of A302265.

Links

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

Formula

Empirical: a(n) = 3*a(n-1) +14*a(n-2) -9*a(n-3) -54*a(n-4) -10*a(n-5) +65*a(n-6) +17*a(n-7) -8*a(n-8) -2*a(n-9) -31*a(n-10) -7*a(n-11) +9*a(n-12) for n>13.

Example

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

Crossrefs

Cf. A302265.

Sequence in context: A301843 A332430 A302070 * A113154 A302966 A337367

Adjacent sequences: A302264 A302265 A302266 * A302268 A302269 A302270

Keyword

nonn

Author

R. H. Hardin, Apr 04 2018

Status

approved