A202892 Number of (n+2)X4 binary arrays avoiding patterns 001 and 010 in rows, columns and nw-to-se diagonals.

258, 844, 3264, 11792, 41125, 146033, 518500, 1829248, 6456790, 22804970, 80487561, 284029242, 1002372834, 3537239577, 12482044458, 44046176233, 155426964450, 548457225605, 1935348475463, 6829275410361, 24098489355181

Offset

1,1

Links

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

Formula

Empirical: a(n) = 6*a(n-1) -15*a(n-2) +51*a(n-3) -146*a(n-4) +236*a(n-5) -502*a(n-6) +942*a(n-7) -805*a(n-8) +1335*a(n-9) -1767*a(n-10) -758*a(n-11) -701*a(n-12) +972*a(n-13) +5841*a(n-14) +1878*a(n-15) -2262*a(n-16) -9338*a(n-17) -8614*a(n-18) +3129*a(n-19) +12283*a(n-20) +12775*a(n-21) +1994*a(n-22) -12403*a(n-23) -13073*a(n-24) -4954*a(n-25) +6289*a(n-26) +9875*a(n-27) +4484*a(n-28) -1723*a(n-29) -4199*a(n-30) -2545*a(n-31) +8*a(n-32) +1153*a(n-33) +603*a(n-34) +228*a(n-35) -181*a(n-36) -76*a(n-37) -12*a(n-38) -19*a(n-39) +16*a(n-40) -8*a(n-41) +4*a(n-42) for n>43.

Example

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

Crossrefs

Column 2 of A202898.

Sequence in context: A173981 A339538 A252264 * A158230 A209945 A233306

Adjacent sequences: A202889 A202890 A202891 * A202893 A202894 A202895

Keyword

nonn

Author

R. H. Hardin, Dec 25 2011

Status

approved