A240644 Number of nX3 0..1 arrays with no element equal to the same number of vertical neighbors as horizontal neighbors, with new values 0..1 introduced in row major order

1, 2, 6, 8, 23, 60, 149, 396, 1050, 2814, 7571, 20372, 54879, 147946, 399002, 1076312, 2903613, 7833652, 21135287, 57024772, 153859830, 415135862, 1120101045, 3022215348, 8154444873, 22002086130, 59365425382, 160178219728, 432188727639

Offset

1,2

Comments

Column 3 of A240649

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -3*a(n-2) -2*a(n-3) +2*a(n-4) +2*a(n-5) -7*a(n-6) -8*a(n-7) +15*a(n-8) +4*a(n-9) -8*a(n-10) -4*a(n-11) +15*a(n-12) +8*a(n-13) -7*a(n-14) -2*a(n-15) +2*a(n-16) +2*a(n-17) -3*a(n-18) -4*a(n-19) -a(n-20)

Example

Some solutions for n=4
..0..1..0....0..0..0....0..1..0....0..0..0....0..1..0....0..1..0....0..0..0
..0..1..0....1..0..1....0..1..0....1..1..1....0..1..0....0..1..0....1..0..1
..1..0..1....1..0..1....0..1..0....0..1..0....1..1..1....0..1..0....1..0..1
..1..0..1....1..0..1....0..1..0....0..1..0....0..0..0....1..1..1....0..0..0

Crossrefs

Sequence in context: A137072 A153802 A217019 * A344914 A068496 A340810

Adjacent sequences: A240641 A240642 A240643 * A240645 A240646 A240647

Keyword

nonn

Author

R. H. Hardin, Apr 09 2014

Status

approved