A283516 Number of nX2 0..1 arrays with no 1 equal to more than three of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements.

0, 0, 1, 5, 28, 145, 703, 3288, 14980, 66958, 294864, 1283142, 5529698, 23637592, 100350059, 423511851, 1778210188, 7432635711, 30943479193, 128365649488, 530810149910, 2188638842860, 9000532494016, 36925016172060, 151153394192532

Offset

1,4

Comments

Column 2 of A283522.

Links

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

Formula

Empirical: a(n) = 9*a(n-1) -18*a(n-2) -24*a(n-3) +39*a(n-4) +75*a(n-5) +69*a(n-6) +93*a(n-7) +99*a(n-8) +67*a(n-9) +45*a(n-10) +33*a(n-11) +16*a(n-12) +6*a(n-13) +3*a(n-14) +a(n-15)

Example

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

Crossrefs

Cf. A283522.

Sequence in context: A037682 A271686 A272288 * A126699 A267828 A164537

Adjacent sequences: A283513 A283514 A283515 * A283517 A283518 A283519

Keyword

nonn

Author

R. H. Hardin, Mar 09 2017

Status

approved