A280476 Number of n X 4 0..2 arrays with no element unequal to a strict majority of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.

6, 63, 997, 15104, 214635, 2886700, 37224679, 464804972, 5658641517, 67497024458, 791686330307, 9155901061480, 104627294693465, 1183339450854998, 13264070830389055, 147510583604457748, 1629077899911720149

Offset

1,1

Comments

Column 4 of A280480.

Links

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

Formula

Empirical: a(n) = 51*a(n-1) -1155*a(n-2) +15629*a(n-3) -144180*a(n-4) +980916*a(n-5) -5175036*a(n-6) +21885648*a(n-7) -75880896*a(n-8) +219014768*a(n-9) -531595200*a(n-10) +1091740992*a(n-11) -1902278464*a(n-12) +2810785536*a(n-13) -3508065024*a(n-14) +3668507648*a(n-15) -3171179520*a(n-16) +2217664512*a(n-17) -1211863040*a(n-18) +487784448*a(n-19) -128974848*a(n-20) +16777216*a(n-21) for n>22.

Example

Some solutions for n=4
..0..0..0..1. .0..0..1..1. .0..0..0..1. .0..1..1..1. .0..1..0..0
..0..0..1..0. .0..0..0..2. .0..0..1..1. .1..1..1..0. .0..0..2..2
..2..2..0..1. .1..1..2..2. .2..0..0..2. .1..2..0..0. .0..2..2..0
..2..0..1..1. .1..2..2..2. .0..0..0..0. .2..2..2..2. .0..0..0..0

Crossrefs

Cf. A280480.

Sequence in context: A107995 A166893 A213644 * A295241 A271607 A360481

Adjacent sequences: A280473 A280474 A280475 * A280477 A280478 A280479

Keyword

nonn

Author

R. H. Hardin, Jan 04 2017

Status

approved