A302273 Number of n X 3 0..1 arrays with every element equal to 1, 2 or 4 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

1, 7, 22, 79, 269, 942, 3401, 12283, 43006, 156939, 565249, 2007662, 7307653, 26305407, 94096702, 341521831, 1229036517, 4413205998, 15980067713, 57514505187, 206942767678, 748087603299, 2693270343273, 9700931065070

Offset

1,2

Comments

Column 3 of A302278.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +5*a(n-2) +26*a(n-3) -66*a(n-4) -86*a(n-5) +79*a(n-6) +14*a(n-7) +13*a(n-8) -168*a(n-9) +250*a(n-10) +428*a(n-11) -232*a(n-12) -24*a(n-13) -160*a(n-14) +160*a(n-15) -256*a(n-16) -384*a(n-17) +256*a(n-18).

Example

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

Crossrefs

Cf. A302278.

Sequence in context: A278767 A286186 A282035 * A151822 A302724 A305083

Adjacent sequences: A302270 A302271 A302272 * A302274 A302275 A302276

Keyword

nonn

Author

R. H. Hardin, Apr 04 2018

Status

approved