A231249 Number of 4Xn 0..3 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero

0, 20, 552, 5992, 76264, 1081934, 15270416, 213355654, 2979297186, 41637993524, 582001470148, 8134516660856, 113692450572670, 1589033640398564, 22209327313491742, 310411398997352946, 4338502347339782972

Offset

1,2

Comments

Row 4 of A231246

Links

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

Formula

Empirical: a(n) = 15*a(n-1) -25*a(n-2) +148*a(n-3) +122*a(n-4) -1205*a(n-5) -2750*a(n-6) -2119*a(n-7) +1020*a(n-8) +18937*a(n-9) +50454*a(n-10) +61769*a(n-11) -6359*a(n-12) -151941*a(n-13) -166619*a(n-14) +30896*a(n-15) +129574*a(n-16) +38876*a(n-17) -30440*a(n-18) -29584*a(n-19) -9952*a(n-20) +1728*a(n-21) +1280*a(n-22) for n>23

Example

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

Crossrefs

Sequence in context: A202920 A210486 A047682 * A012568 A259057 A184123

Adjacent sequences: A231246 A231247 A231248 * A231250 A231251 A231252

Keyword

nonn

Author

R. H. Hardin, Nov 06 2013

Status

approved