A274857 Number of nX7 0..2 arrays with no element equal to any value at offset (-1,0) (0,-1) or (-2,-2) and new values introduced in order 0..2.

32, 729, 542, 2585, 12102, 58775, 289494, 1426688, 7031552, 34766640, 172447382, 856198165, 4249077675, 21078145330, 104568950459, 518896515145, 2575174869347, 12779650282427, 63417621140877, 314701428995532

Offset

1,1

Comments

Column 7 of A274858.

Links

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

Formula

Empirical: a(n) = 21*a(n-1) -209*a(n-2) +1330*a(n-3) -6059*a(n-4) +20839*a(n-5) -55739*a(n-6) +118287*a(n-7) -202495*a(n-8) +284119*a(n-9) -331806*a(n-10) +326718*a(n-11) -273224*a(n-12) +193798*a(n-13) -115270*a(n-14) +56258*a(n-15) -21837*a(n-16) +6481*a(n-17) -1404*a(n-18) +210*a(n-19) -20*a(n-20) +a(n-21) for n>24

Example

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

Crossrefs

Cf. A274858.

Sequence in context: A062261 A060624 A351384 * A274754 A008789 A207996

Adjacent sequences: A274854 A274855 A274856 * A274858 A274859 A274860

Keyword

nonn

Author

R. H. Hardin, Jul 09 2016

Status

approved