A231249 - OEIS

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

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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