A185838 Number of (n+1)X3 0..2 arrays with every 2X2 subblock trace equal to some horizontal or vertical neighbor 2X2 subblock trace

171, 1773, 20097, 222003, 2506851, 28276065, 319126401, 3601102725, 40637462859, 458593005339, 5175210065355, 58401927953289, 659062151345205, 7437478883246883, 83931531974296659, 947162573247121263

Offset

1,1

Comments

Column 2 of A185845

Links

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

Formula

Empirical: a(n)=16*a(n-1)-81*a(n-2)+354*a(n-3)-423*a(n-4)-1212*a(n-5)+11545*a(n-6)-26105*a(n-7)+39610*a(n-8)-45245*a(n-9)+44999*a(n-10)-392268*a(n-11)+783566*a(n-12)-3468627*a(n-13)+6420741*a(n-14)-6371674*a(n-15)+3563213*a(n-16)+9619160*a(n-17)-4795228*a(n-18)+26611700*a(n-19)-73660858*a(n-20)+21692189*a(n-21)-69651145*a(n-22)+122552900*a(n-23)+38894274*a(n-24)+38755104*a(n-25)-143115104*a(n-26)-47053152*a(n-27)+38096928*a(n-28)+80391744*a(n-29)-23458176*a(n-30)-26341632*a(n-31)+12151296*a(n-32)-1354752*a(n-33)

Example

Some solutions for 5X3
..2..1..0....0..0..2....1..1..0....2..1..0....1..0..2....1..1..0....1..0..0
..2..1..2....0..0..0....2..1..2....1..1..2....0..1..2....2..2..2....0..1..2
..1..1..1....2..0..2....2..0..2....0..2..2....0..2..1....2..2..2....2..2..2
..0..1..1....1..0..2....2..0..1....2..2..2....2..2..0....2..2..2....0..1..1
..0..1..0....1..0..1....0..0..1....2..0..2....0..0..0....2..2..2....2..2..1

Crossrefs

Sequence in context: A221754 A036518 A187133 * A199902 A251223 A186868

Adjacent sequences: A185835 A185836 A185837 * A185839 A185840 A185841

Keyword

nonn

Author

R. H. Hardin Feb 05 2011

Status

approved