A235015 - OEIS

A235015

Number of (n+1) X (6+1) 0..4 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 3, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

4456, 6088, 8760, 13912, 23016, 40968, 74888, 144184, 283832, 581720, 1219560, 2643112, 5857032, 13329432, 30923000, 73178104, 175729256, 427827272, 1052243592, 2611236664, 6523282488, 16387734744, 41341915880, 104653471144

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OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) + a(n-2) - 38*a(n-3) + 33*a(n-4) + 97*a(n-5) - 127*a(n-6) - 88*a(n-7) + 154*a(n-8) + 12*a(n-9) - 48*a(n-10).

Empirical g.f.: 8*x*(557 - 2024*x - 3267*x^2 + 16669*x^3 + 3624*x^4 - 48535*x^5 + 7748*x^6 + 57484*x^7 - 12768*x^8 - 21712*x^9) / ((1 - x)*(1 - 2*x)*(1 - x - x^2)*(1 - 2*x^2)*(1 - 3*x^2)*(1 - x - 4*x^2)). - Colin Barker, Oct 17 2018

EXAMPLE

Some solutions for n=4:

4 0 4 0 4 0 2 0 2 1 3 1 2 1 0 1 2 0 2 0 4

2 1 2 1 2 1 0 1 0 2 1 2 0 2 4 2 0 1 0 1 2

0 2 0 2 0 2 4 0 2 1 3 1 2 1 2 3 4 2 4 2 0

2 1 2 1 2 1 0 2 1 3 2 3 1 3 4 2 0 1 0 1 2

4 0 4 0 4 0 2 1 3 2 4 2 3 2 2 3 4 2 4 2 0

CROSSREFS

Column 6 of A235017.

Sequence in context: A279042 A253697 A253704 * A185767 A089202 A250977

Adjacent sequences: A235012 A235013 A235014 * A235016 A235017 A235018

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 02 2014

STATUS

approved