A230991 Number of nX3 0..3 arrays x(i,j) with each element horizontally, vertically 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, 2, 14, 182, 2364, 36020, 513774, 7466956, 108082822, 1565657608, 22676496408, 328443902490, 4757195184330, 68903138021262, 997992766403828, 14454923305122306, 209365029835258358, 3032442137209416056

Offset

1,2

Comments

Column 3 of A230994

Links

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

Formula

Empirical: a(n) = 23*a(n-1) -149*a(n-2) +383*a(n-3) -104*a(n-4) +317*a(n-5) -30985*a(n-6) +256815*a(n-7) -992410*a(n-8) +1272169*a(n-9) +5426136*a(n-10) -34942372*a(n-11) +116124441*a(n-12) -308887574*a(n-13) +758615563*a(n-14) -1805037482*a(n-15) +4125802269*a(n-16) -8011638180*a(n-17) +14758066106*a(n-18) -45484548705*a(n-19) +120405912285*a(n-20) -128300026622*a(n-21) -6060650964*a(n-22) +33555194302*a(n-23) -93703260352*a(n-24) +462538307466*a(n-25) -559690521304*a(n-26) -163640092140*a(n-27) +548638490999*a(n-28) +557307876237*a(n-29) -524363364551*a(n-30) -859741374611*a(n-31) +1135665697589*a(n-32) +531682029352*a(n-33) -703229647302*a(n-34) -261109826702*a(n-35) +344415159214*a(n-36) +296398095252*a(n-37) +72247983516*a(n-38) -29069776848*a(n-39) -92977319528*a(n-40) +16884602640*a(n-41) +38376325040*a(n-42) -26514851136*a(n-43) -35845053248*a(n-44) -21519041280*a(n-45) -7309768192*a(n-46) -1399013376*a(n-47) -141680640*a(n-48) -5963776*a(n-49)

Example

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

Crossrefs

Sequence in context: A109520 A370054 A210097 * A258872 A372246 A000807

Adjacent sequences: A230988 A230989 A230990 * A230992 A230993 A230994

Keyword

nonn

Author

R. H. Hardin, Nov 02 2013

Status

approved