A205604 Number of (n+1)X4 0..3 arrays with every 2X2 subblock having the same number of equal edges as its horizontal neighbors and a different number from its vertical neighbors, and new values 0..3 introduced in row major order

443, 9688, 229445, 5470216, 131086803, 3128383392, 74880118862, 1789102516698, 42797416252738, 1022912102229384, 24463500789654523, 584810372631311890, 13984289373326702867, 334330210257654099548, 7994180856499923543924

Offset

1,1

Comments

Column 3 of A205609

Links

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

Formula

Empirical: a(n) = 471*a(n-2) +3520*a(n-3) -9982*a(n-4) -369876*a(n-5) -1286266*a(n-6) +12652252*a(n-7) +62302467*a(n-8) -172499788*a(n-9) -969353689*a(n-10) +1140886196*a(n-11) +5920757684*a(n-12) -6427855248*a(n-13) -4731229724*a(n-14) +58949652912*a(n-15) -43707104144*a(n-16) -108388914768*a(n-17) +316917783552*a(n-18) -1562540422272*a(n-19) -4852781707392*a(n-20) +2639798305920*a(n-21) +15547627524096*a(n-22) +8515882377216*a(n-23) -8609700003840*a(n-24) -9567761596416*a(n-25) -2412483969024*a(n-26) for n>27

Example

Some solutions for n=4
..0..0..0..0....0..0..1..2....0..0..0..0....0..1..0..1....0..0..0..0
..1..0..2..2....3..2..1..3....0..0..0..0....1..0..1..2....0..0..0..0
..1..3..3..0....1..0..2..0....1..1..0..1....1..2..1..3....1..0..1..0
..1..3..0..0....1..3..2..1....0..2..2..1....0..3..2..0....1..3..3..3
..1..2..2..3....3..0..3..2....2..2..1..1....0..1..2..3....1..3..0..3

Crossrefs

Sequence in context: A158321 A293978 A345307 * A205435 A098254 A242540

Adjacent sequences: A205601 A205602 A205603 * A205605 A205606 A205607

Keyword

nonn

Author

R. H. Hardin Jan 29 2012

Status

approved