A275271 Number of 7Xn 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,1) or (-1,-1) and new values introduced in order 0..2.

365, 1320, 22844, 409728, 8391716, 161725644, 3224773976, 63143699424, 1248576812224, 24559019167784, 484440702701304, 9541263324553052, 188074099882897920, 3705606976727045064, 73028693578450670888

Offset

1,1

Comments

Row 7 of A275266.

Links

R. H. Hardin, Table of n, a(n) for n = 1..148

Formula

Empirical: a(n) = 21*a(n-1) +48*a(n-2) -1991*a(n-3) +11659*a(n-4) -14171*a(n-5) -128662*a(n-6) +689002*a(n-7) -706983*a(n-8) -4268873*a(n-9) +10877433*a(n-10) -17644881*a(n-11) +81344927*a(n-12) -130013786*a(n-13) +156595402*a(n-14) +113088522*a(n-15) -2082695943*a(n-16) +2912724245*a(n-17) -8721718373*a(n-18) +9200100358*a(n-19) +2338527368*a(n-20) +31879719935*a(n-21) +58651417388*a(n-22) +9088289076*a(n-23) +12623664585*a(n-24) -121551613750*a(n-25) -89132646098*a(n-26) -109279416317*a(n-27) -24885539062*a(n-28) +43358373330*a(n-29) +77540289847*a(n-30) +74999417020*a(n-31) +32061565379*a(n-32) +7553640937*a(n-33) -6937228733*a(n-34) -7608254513*a(n-35) -6975958381*a(n-36) -3411225596*a(n-37) -1881561696*a(n-38) -603608528*a(n-39) -219594032*a(n-40) -68268736*a(n-41) -9248000*a(n-42) -5030912*a(n-43) for n>45

Example

Some solutions for n=3
..0..1..2. .0..1..0. .0..1..0. .0..1..2. .0..1..0. .0..1..0. .0..1..0
..0..1..0. .0..1..2. .2..1..0. .0..1..0. .2..1..2. .0..1..2. .2..1..0
..0..1..0. .0..1..0. .0..1..0. .0..1..2. .0..1..0. .2..1..0. .2..1..2
..2..1..0. .0..1..2. .2..1..2. .0..1..0. .0..1..2. .0..1..2. .0..1..0
..2..1..2. .2..1..0. .0..1..0. .2..1..0. .2..2..0. .0..1..0. .0..1..0
..2..1..0. .0..1..2. .0..1..0. .0..1..2. .0..1..0. .0..1..0. .0..1..0
..2..0..2. .2..1..2. .0..1..2. .0..1..0. .1..1..0. .0..2..0. .0..1..0

Crossrefs

Cf. A275266.

Sequence in context: A033172 A033173 A043443 * A062681 A259948 A203806

Adjacent sequences: A275268 A275269 A275270 * A275272 A275273 A275274

Keyword

nonn

Author

R. H. Hardin, Jul 21 2016

Status

approved