A317761 Number of n X 5 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

16, 42, 52, 72, 109, 177, 302, 532, 955, 1733, 3164, 5796, 10637, 19541, 35918, 66040, 121443, 223345, 410772, 755504, 1389565, 2555785, 4700798, 8646092, 15902619, 29249453, 53798108, 98950124, 181997629, 334745805, 615693502, 1132436880

Offset

1,1

Comments

Column 5 of A317764.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) - a(n-4) for n > 6.

Example

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

Crossrefs

Cf. A317764.

Sequence in context: A200408 A280184 A228685 * A318340 A318072 A304954

Adjacent sequences: A317758 A317759 A317760 * A317762 A317763 A317764

Keyword

nonn

Author

R. H. Hardin, Aug 06 2018

Status

approved