

A196072


Number of n X 2 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 0,3,2,1,4 for x=0,1,2,3,4.


1



0, 1, 2, 0, 6, 2, 8, 12, 10, 32, 26, 58, 82, 104, 204, 238, 424, 606, 870, 1438, 1952, 3156, 4602, 6848, 10634, 15354, 23794, 35192, 52844, 80254, 118744, 180686, 269382, 405118, 610576, 911988, 1377066, 2061328, 3099290, 4659546, 6984594, 10512968
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,3


COMMENTS

Every 0 is next to 0 0's, every 1 is next to 1 3's, every 2 is next to 2 2's, every 3 is next to 3 1's, every 4 is next to 4 4's.


LINKS



FORMULA

Empirical: a(n) = a(n2) +a(n3) +2*a(n5).
Empirical g.f.: x^2*(1 + 2*x  x^2 + 3*x^3) / (1  x^2  x^3  2*x^5).  Colin Barker, May 08 2018


EXAMPLE

All solutions for n=5:
..2..2....2..2....1..0....1..0....0..1....0..1
..2..2....2..2....3..1....3..1....1..3....1..3
..0..1....1..0....1..1....1..0....0..1....1..1
..1..3....3..1....1..3....2..2....2..2....3..1
..0..1....1..0....0..1....2..2....2..2....1..0


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



