A300501 Number of nX3 0..1 arrays with every element equal to 0, 1, 3 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

3, 2, 4, 7, 6, 17, 34, 57, 80, 164, 302, 526, 885, 1647, 2996, 5296, 9259, 16753, 30075, 53468, 94738, 169873, 303898, 541631, 964444, 1724067, 3079837, 5493915, 9797538, 17495715, 31235953, 55738172, 99453077, 177534256, 316897514, 565552854

Offset

1,1

Comments

Column 3 of A300506.

Links

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

Formula

Empirical: a(n) = 5*a(n-2) +2*a(n-3) -7*a(n-4) -8*a(n-5) -5*a(n-6) +10*a(n-7) +34*a(n-8) +10*a(n-9) -54*a(n-10) -52*a(n-11) +26*a(n-12) +72*a(n-13) +26*a(n-14) -40*a(n-15) -49*a(n-16) -16*a(n-17) +21*a(n-18) +36*a(n-19) +14*a(n-20) -12*a(n-21) -10*a(n-22) -4*a(n-23) -a(n-24) +2*a(n-25) +a(n-26) for n>31

Example

All solutions for n=5
..0..1..0. .0..0..0. .0..1..0. .0..1..0. .0..0..1. .0..0..0
..0..0..1. .1..0..0. .0..0..1. .0..0..1. .1..1..0. .1..0..0
..0..0..0. .1..0..1. .0..1..0. .0..0..1. .0..1..1. .0..1..0
..1..0..0. .0..0..1. .0..0..1. .1..0..0. .0..1..1. .1..0..0
..0..1..0. .0..0..0. .0..0..0. .0..1..1. .1..0..1. .0..1..0

Crossrefs

Cf. A300506.

Sequence in context: A170950 A276954 A276944 * A356957 A158441 A349368

Adjacent sequences: A300498 A300499 A300500 * A300502 A300503 A300504

Keyword

nonn

Author

R. H. Hardin, Mar 07 2018

Status

approved