A210271 Half the number of (n+1)X4 0..2 arrays with every 2X2 subblock having two or three distinct clockwise edge differences

2130, 113248, 6028871, 321050788, 17097482699, 910532241954, 48490791961375, 2582399328204990, 137526868179029404, 7324056952893265933, 390046040465491252479, 20772082296310330599391, 1106226850689067938595724

Offset

1,1

Comments

Column 3 of A210276

Links

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

Formula

Empirical: a(n) = 48*a(n-1) +480*a(n-2) -9807*a(n-3) -58253*a(n-4) +657082*a(n-5) +2138431*a(n-6) -18778839*a(n-7) -19795420*a(n-8) +235514744*a(n-9) -62769938*a(n-10) -1259927930*a(n-11) +1276469157*a(n-12) +2637995603*a(n-13) -4298139072*a(n-14) -1484220465*a(n-15) +5231313990*a(n-16) -949603112*a(n-17) -2426962356*a(n-18) +931229528*a(n-19) +400609008*a(n-20) -188316850*a(n-21) -12522776*a(n-22) +5412968*a(n-23) -237208*a(n-24) -448*a(n-25)

Example

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

Crossrefs

Sequence in context: A278797 A251134 A338070 * A066817 A110024 A260068

Adjacent sequences: A210268 A210269 A210270 * A210272 A210273 A210274

Keyword

nonn

Author

R. H. Hardin Mar 19 2012

Status

approved