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A274067
Number of n X 3 0..2 arrays with no three equal values forming an isosceles triangle, and new values introduced in 0..2 order.
1
5, 50, 136, 111, 97, 235, 197, 389, 305, 589, 447, 823, 621, 1089, 827, 1387, 1065, 1717, 1335, 2079, 1637, 2473, 1971, 2899, 2337, 3357, 2735, 3847, 3165, 4369, 3627, 4923, 4121, 5509, 4647, 6127, 5205, 6777, 5795, 7459, 6417, 8173, 7071, 8919, 7757, 9697
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = a(n-1) + 2*a(n-2) - 2*a(n-3) - a(n-4) + a(n-5) for n>13.
Empirical g.f.: x*(5 + 45*x + 76*x^2 - 115*x^3 - 181*x^4 + 233*x^5 + 76*x^6 - 109*x^7 - 22*x^8 + 38*x^9 - 12*x^10 - 2*x^12) / ((1 - x)^3*(1 + x)^2). - Colin Barker, Jan 30 2019
EXAMPLE
Some solutions for n=3:
..0..0..1. .0..0..0. .0..1..1. .0..1..1. .0..1..2. .0..1..1. .0..1..2
..2..1..0. .1..2..2. .2..0..2. .2..0..2. .2..0..2. .0..2..2. .0..1..2
..2..1..0. .2..1..1. .2..0..2. .2..1..0. .2..1..0. .2..1..1. .1..2..0
CROSSREFS
Column 3 of A274068.
Sequence in context: A136919 A136920 A358686 * A069540 A366678 A267640
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jun 09 2016
STATUS
approved