A281931 Number of nX3 0..1 arrays with no element equal to more than four of its king-move neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

0, 1, 20, 312, 3573, 31410, 252630, 1925590, 14065552, 99735307, 691339079, 4705890596, 31562889402, 209107683151, 1370993621183, 8908621893421, 57438444240641, 367809712917088, 2341050421702590, 14819986285211521

Offset

1,3

Comments

Column 3 of A281936.

Links

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

Formula

Empirical: a(n) = 15*a(n-1) -63*a(n-2) +23*a(n-3) +3*a(n-4) +1161*a(n-5) +208*a(n-6) -2013*a(n-7) -8424*a(n-8) -6999*a(n-9) +7797*a(n-10) +25689*a(n-11) +44356*a(n-12) +27282*a(n-13) -498*a(n-14) -60721*a(n-15) -115722*a(n-16) -113223*a(n-17) -120471*a(n-18) -77700*a(n-19) -35280*a(n-20) -21952*a(n-21) for n>26

Example

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

Crossrefs

Cf. A281936.

Sequence in context: A282372 A361293 A240799 * A034094 A011197 A054621

Adjacent sequences: A281928 A281929 A281930 * A281932 A281933 A281934

Keyword

nonn

Author

R. H. Hardin, Feb 02 2017

Status

approved