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A281248
Number of nX3 0..2 arrays with no element equal to more than one of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards.
1
0, 12, 443, 8489, 105368, 1113148, 10598099, 94350141, 800540848, 6552843938, 52163574440, 406096164959, 3104415588852, 23374506589595, 173753114036173, 1277461524990825, 9303058981853048, 67186844864693416, 481669905249353054
OFFSET
1,2
COMMENTS
Column 3 of A281251.
LINKS
FORMULA
Empirical: a(n) = 14*a(n-1) -37*a(n-2) -137*a(n-3) +133*a(n-4) +1003*a(n-5) +3804*a(n-6) +5187*a(n-7) -2352*a(n-8) -9604*a(n-9) -8788*a(n-10) +20660*a(n-11) +73716*a(n-12) +13836*a(n-13) -107898*a(n-14) -90512*a(n-15) +29977*a(n-16) +283636*a(n-17) +190689*a(n-18) -510519*a(n-19) -322065*a(n-20) +553505*a(n-21) +160238*a(n-22) -387019*a(n-23) +48576*a(n-24) +108354*a(n-25) -163512*a(n-26) -22652*a(n-27) +75376*a(n-28) +6952*a(n-29) +12160*a(n-30) +24352*a(n-31) +7936*a(n-32) +2432*a(n-33) +2048*a(n-34) +512*a(n-35) for n>45
EXAMPLE
Some solutions for n=4
..0..1..2. .0..1..0. .0..1..0. .0..1..2. .0..0..1. .0..0..1. .0..1..0
..0..2..1. .0..2..0. .1..0..1. .2..0..1. .1..1..2. .1..1..2. .0..0..2
..1..2..2. .0..1..2. .0..1..2. .2..0..1. .2..2..0. .0..2..0. .2..1..2
..2..1..0. .0..2..0. .0..2..1. .1..0..1. .1..1..0. .1..2..0. .1..0..0
CROSSREFS
Cf. A281251.
Sequence in context: A159534 A303922 A246502 * A338960 A195616 A126603
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 18 2017
STATUS
approved