login
A302166
Number of 4Xn 0..1 arrays with every element equal to 0, 1 or 3 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
1
8, 10, 17, 29, 51, 109, 206, 407, 791, 1584, 3104, 6165, 12131, 24059, 47443, 93958, 185498, 367087, 725156, 1434386, 2834565, 5605574, 11079494, 21907412, 43304842, 85620318, 169257166, 334632998, 661534245, 1307869617, 2585565413, 5111662053
OFFSET
1,1
COMMENTS
Row 4 of A302163.
LINKS
FORMULA
Empirical: a(n) = a(n-1) +a(n-2) +8*a(n-4) -4*a(n-5) -4*a(n-6) -a(n-7) -22*a(n-8) +a(n-9) +5*a(n-10) +2*a(n-11) +28*a(n-12) +6*a(n-13) -3*a(n-14) -3*a(n-15) -17*a(n-16) -4*a(n-17) +2*a(n-18) +2*a(n-19) +4*a(n-20) -a(n-22) for n>23
EXAMPLE
Some solutions for n=5
..0..1..1..0..0. .0..0..1..1..0. .0..1..0..1..0. .0..1..0..1..0
..0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0. .1..1..0..1..1
..0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0. .0..1..0..1..0
..0..1..0..0..1. .0..1..0..0..1. .0..1..0..0..1. .0..1..0..1..0
CROSSREFS
Cf. A302163.
Sequence in context: A049510 A121846 A059094 * A374622 A287270 A299988
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 02 2018
STATUS
approved