A187133 Number of (n+1)X3 0..2 arrays with every 2X2 subblock trace equal to exactly one or two horizontal and vertical neighbor 2X2 subblock traces

171, 1773, 19062, 182214, 1853892, 18740754, 189091422, 1908891288, 19278208206, 194645680218, 1965399983316, 19844830788804, 200378939196348, 2023260613838154, 20429301340509606, 206278735833598914

Offset

1,1

Comments

Column 2 of A187140

Links

R. H. Hardin, Table of n, a(n) for n = 1..200

Formula

Empirical: a(n)=8*a(n-1)+7*a(n-2)+57*a(n-3)+830*a(n-4)-760*a(n-5)+13856*a(n-6)-16412*a(n-7)-20781*a(n-8)-279409*a(n-9)-286716*a(n-10)-177533*a(n-11)-1234545*a(n-12)+8386114*a(n-13)+27271210*a(n-14)+14619241*a(n-15)+23883593*a(n-16)-184245010*a(n-17)-273527466*a(n-18)-929089851*a(n-19)-1459165167*a(n-20)+7806772227*a(n-21)-3902405566*a(n-22)+12705482310*a(n-23)+66192396*a(n-24)-23799404280*a(n-25)-23221742848*a(n-26)-85333270112*a(n-27)+154491695232*a(n-28)+59114655488*a(n-29)+45146716672*a(n-30)-94877119488*a(n-31)-212159176704*a(n-32)+234619213824*a(n-33)-294853865472*a(n-34)+326049988608*a(n-35)-218420084736*a(n-36)+290221719552*a(n-37)-171228266496*a(n-38)

Example

Some solutions for 4X3
..2..2..0....0..1..2....0..2..0....1..0..0....0..2..2....1..1..1....1..2..0
..2..0..0....1..1..1....0..1..1....1..0..2....0..2..0....2..1..0....1..2..0
..0..0..2....1..0..1....1..1..2....0..0..2....2..2..1....1..0..0....1..2..0
..1..1..1....1..1..2....0..0..2....2..1..1....0..1..1....1..1..1....1..2..1

Crossrefs

Sequence in context: A251329 A221754 A036518 * A185838 A199902 A251223

Adjacent sequences: A187130 A187131 A187132 * A187134 A187135 A187136

Keyword

nonn

Author

R. H. Hardin Mar 05 2011

Status

approved