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A239399
Number of n X 2 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, modulo 4.
1
4, 23, 129, 698, 3805, 20818, 113774, 621754, 3399032, 18582965, 101593258, 555419633, 3036563927, 16601366841, 90762262155, 496211843813, 2712870511114, 14831702705726, 81087325012785, 443317575022163, 2423689199017701, 13250702601112477, 72443743963082659, 396061718589309511
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = 9*a(n-1) -28*a(n-2) +74*a(n-3) -181*a(n-4) +236*a(n-5) -261*a(n-6) +234*a(n-7) +200*a(n-8) -279*a(n-9) +104*a(n-10) -268*a(n-11) -36*a(n-12) +156*a(n-13) +104*a(n-14) -32*a(n-15) -16*a(n-16).
EXAMPLE
Some solutions for n=5:
..3..1....0..0....0..3....0..0....3..3....3..3....3..3....3..1....3..1....0..0
..0..0....3..1....3..3....0..3....3..3....0..0....3..3....0..2....0..2....0..0
..2..2....2..2....3..2....0..2....3..2....2..0....2..2....0..2....0..2....0..0
..2..0....2..2....3..1....0..2....0..3....0..3....3..1....2..0....0..0....3..3
..3..2....3..1....2..0....0..0....2..0....0..2....3..1....0..0....0..2....0..0
CROSSREFS
Column 2 of A239405.
Sequence in context: A236421 A227639 A291026 * A193808 A038723 A302761
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 17 2014
STATUS
approved