A240279 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or two plus the sum of elements above it or zero plus the sum of the elements diagonally to its northwest, modulo 4

2, 8, 19, 38, 114, 251, 612, 1656, 3758, 9630, 24258, 57548, 146898, 360946, 880960, 2217967, 5429271, 13419200, 33424298, 82079277, 203571196, 504206276, 1242741927, 3081338174, 7616293969, 18815746878, 46600839533, 115150972966

Offset

1,1

Comments

Column 2 of A240284

Links

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

Formula

Empirical: a(n) = 3*a(n-2) +10*a(n-3) -3*a(n-4) -6*a(n-5) -3*a(n-6) +8*a(n-7) -7*a(n-8) -9*a(n-9) -4*a(n-10) +13*a(n-11) -14*a(n-12) +17*a(n-13) -a(n-15)

Example

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

Crossrefs

Sequence in context: A031327 A193389 A030504 * A327728 A372485 A000158

Adjacent sequences: A240276 A240277 A240278 * A240280 A240281 A240282

Keyword

nonn

Author

R. H. Hardin, Apr 03 2014

Status

approved