A205921 Number of (n+1)X4 0..3 arrays with the number of clockwise edge increases in every 2X2 subblock equal to one, and every 2X2 determinant nonzero

1828, 15561, 67372, 583542, 2570656, 22176946, 98991836, 849405824, 3837701468, 32699583658, 149381183572, 1262924581602, 5828725185288, 48878384865034, 227757652474132, 1894271871158330, 8906948226136424, 73477236256867430

Offset

1,1

Comments

Column 3 of A205926

Links

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

Formula

Empirical: a(n) = 119*a(n-2) +4*a(n-3) -5671*a(n-4) -332*a(n-5) +140502*a(n-6) +10096*a(n-7) -1946081*a(n-8) -121492*a(n-9) +14700531*a(n-10) +208884*a(n-11) -48951435*a(n-12) +4024144*a(n-13) -33808327*a(n-14) +31195156*a(n-15) +638938677*a(n-16) -621414254*a(n-17) -1072066945*a(n-18) +2389471556*a(n-19) -139848819*a(n-20) -4343451250*a(n-21) -8924971670*a(n-22) +8604001380*a(n-23) +41032270257*a(n-24) -17581883290*a(n-25) -41163594096*a(n-26) +31849234498*a(n-27) -5655121439*a(n-28) -14589728092*a(n-29) +62766122284*a(n-30) -23316251278*a(n-31) -64429104908*a(n-32) +15204624364*a(n-33) +20441413453*a(n-34) +5918648096*a(n-35) +3638449139*a(n-36) -3873731102*a(n-37) -2437649449*a(n-38) +113148320*a(n-39) +628657782*a(n-40) +146176756*a(n-41) -79826388*a(n-42) -11383360*a(n-43) +2290236*a(n-44) +1090352*a(n-45) -354504*a(n-46) -2240*a(n-47) +14112*a(n-48) for n>51

Example

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

Crossrefs

Sequence in context: A167266 A177786 A235073 * A196895 A151644 A031934

Adjacent sequences: A205918 A205919 A205920 * A205922 A205923 A205924

Keyword

nonn

Author

R. H. Hardin Feb 01 2012

Status

approved