A207353 Number of nX3 0..2 arrays avoiding the pattern z+1 z+1 z horizontally and z-1 z-1 z vertically

25, 625, 12468, 244134, 4752484, 92438519, 1799496100, 35036066712, 682243342430, 13285382401983, 258709556131828, 5037920703787458, 98104762268330333, 1910419706227476571, 37202099248377672015

Offset

1,1

Comments

Column 3 of A207358

Links

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

Formula

Empirical: a(n) = 25*a(n-1) -51*a(n-2) -1449*a(n-3) +4497*a(n-4) +56080*a(n-5) -195326*a(n-6) -1092458*a(n-7) +3792966*a(n-8) +14909978*a(n-9) -46825819*a(n-10) -56152375*a(n-11) +266436042*a(n-12) +12699008*a(n-13) -903512455*a(n-14) +68308437*a(n-15) +2829180642*a(n-16) +31615026*a(n-17) -8360870820*a(n-18) +2894963886*a(n-19) +17815106543*a(n-20) -9225942481*a(n-21) -31018293245*a(n-22) +10847234792*a(n-23) +55730103228*a(n-24) -28827979155*a(n-25) -79354744925*a(n-26) +61335560568*a(n-27) +78792129575*a(n-28) -46870664050*a(n-29) -80119327238*a(n-30) +52702395760*a(n-31) +74040744475*a(n-32) -101289126740*a(n-33) -28552713320*a(n-34) +69913137070*a(n-35) -7705787663*a(n-36) -13281937110*a(n-37) +6536331914*a(n-38) -4000594404*a(n-39) -1669071040*a(n-40) +3633531679*a(n-41) -368116652*a(n-42) -525682843*a(n-43) +175019201*a(n-44) -35415944*a(n-45) -23068825*a(n-46) +38059786*a(n-47) -2122737*a(n-48) -4308110*a(n-49) +1225952*a(n-50) +223268*a(n-51) -98608*a(n-52) +45718*a(n-53) +2988*a(n-54) -1920*a(n-55) +1232*a(n-56) -272*a(n-57) +32*a(n-58)

Example

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

Crossrefs

Sequence in context: A068180 A206952 A206729 * A207984 A207196 A207216

Adjacent sequences: A207350 A207351 A207352 * A207354 A207355 A207356

Keyword

nonn

Author

R. H. Hardin Feb 17 2012

Status

approved