A251338 Number of (n+1) X (3+1) 0..3 arrays with every 2 X 2 subblock summing to a nonzero multiple of 3.

2450, 24714, 263824, 3014066, 36988354, 486098916, 6775415354, 98891100062, 1492601141148, 23056819353022, 361731238517094, 5733012694088616, 91461483262635158, 1465335021701616410, 23540870449834141696

Offset

1,1

Comments

Column 3 of A251343.

Links

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

Formula

Empirical: a(n) = 70*a(n-1) -2014*a(n-2) +29857*a(n-3) -222013*a(n-4) +420224*a(n-5) +4865502*a(n-6) -26506713*a(n-7) -28824994*a(n-8) +354961898*a(n-9) +259346784*a(n-10) -2163614680*a(n-11) -3797527072*a(n-12) -191466752*a(n-13) +3397411328*a(n-14) +1811206656*a(n-15) -376104960*a(n-16) -325140480*a(n-17).

Example

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

Crossrefs

Cf. A251343.

Sequence in context: A183629 A274684 A232141 * A035772 A107568 A035875

Adjacent sequences: A251335 A251336 A251337 * A251339 A251340 A251341

Keyword

nonn,changed

Author

R. H. Hardin, Dec 01 2014

Status

approved