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A239407
Number of 3Xn 0..3 arrays with no element equal to one plus the sum of elements to its left or two plus the sum of the elements above it, modulo 4
1
12, 129, 1337, 13977, 144762, 1504399, 15591122, 161801518, 1677624003, 17403195529, 180479056305, 1871997954119, 19414915574725, 201369918597195, 2088509247416759, 21661501410101827, 224664541142404827
OFFSET
1,1
COMMENTS
Row 3 of A239405
LINKS
FORMULA
Empirical: a(n) = 8*a(n-1) +73*a(n-2) -446*a(n-3) -1413*a(n-4) +8070*a(n-5) +12185*a(n-6) -63420*a(n-7) -49358*a(n-8) +220534*a(n-9) +39486*a(n-10) -241802*a(n-11) +244780*a(n-12) -89648*a(n-13) -386680*a(n-14) -228008*a(n-15) +129984*a(n-16) -457816*a(n-17) -1064416*a(n-18) -330768*a(n-19) +556128*a(n-20) -351872*a(n-21) +769280*a(n-22) +407552*a(n-23) -200704*a(n-24) +32768*a(n-25)
EXAMPLE
Some solutions for n=4
..3..3..1..3....3..1..0..0....3..3..1..3....0..3..3..0....0..0..3..3
..0..2..1..3....2..2..3..1....2..2..2..2....0..0..0..3....0..0..0..2
..2..0..1..1....0..2..0..1....2..2..3..1....0..2..0..0....3..3..2..2
CROSSREFS
Sequence in context: A173359 A199037 A099157 * A360878 A163414 A111777
KEYWORD
nonn
AUTHOR
R. H. Hardin, Mar 17 2014
STATUS
approved