A230965 Number of nX3 0..3 arrays x(i,j) with each element horizontally, vertically, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4 and at least one element with value (x(i,j)-1) mod 4, and upper left element zero

0, 22, 328, 8696, 220970, 5669980, 145756934, 3741811720, 96110880966, 2468711100816, 63409119151430, 1628689563351364, 41833654654188898, 1074515649119630140, 27599409261519831938, 708903090985926040460

Offset

1,2

Comments

Column 3 of A230968

Links

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

Formula

Empirical: a(n) = 18*a(n-1) +168*a(n-2) +1201*a(n-3) -6813*a(n-4) -104364*a(n-5) -402136*a(n-6) +223299*a(n-7) +8769145*a(n-8) +35211964*a(n-9) +29468661*a(n-10) -185800821*a(n-11) -841295816*a(n-12) -511278760*a(n-13) +629400915*a(n-14) +2551950301*a(n-15) -807400527*a(n-16) +361780534*a(n-17) +10825055938*a(n-18) +8307552100*a(n-19) +339664426*a(n-20) -14409363244*a(n-21) +28160874016*a(n-22) +40404903680*a(n-23) +34651488280*a(n-24) -53073696960*a(n-25) -81239714944*a(n-26) -69270926688*a(n-27) -43879359040*a(n-28) -14538534912*a(n-29) -3599323392*a(n-30) +964333056*a(n-31) +1059926016*a(n-32) -348233728*a(n-33) +22347776*a(n-34) +31457280*a(n-35) +30932992*a(n-36) -6291456*a(n-37)

Example

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

Crossrefs

Sequence in context: A125479 A047868 A002539 * A019958 A021644 A021834

Adjacent sequences: A230962 A230963 A230964 * A230966 A230967 A230968

Keyword

nonn

Author

R. H. Hardin, Nov 02 2013

Status

approved