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A269411
Number of length-5 0..n arrays with no repeated value greater than or equal to the previous repeated value.
1
12, 159, 804, 2670, 6960, 15477, 30744, 56124, 95940, 155595, 241692, 362154, 526344, 745185, 1031280, 1399032, 1864764, 2446839, 3165780, 4044390, 5107872, 6383949, 7902984, 9698100, 11805300, 14263587, 17115084, 20405154, 24182520
OFFSET
1,1
LINKS
FORMULA
Empirical: a(n) = n^5 + 5*n^4 + (11/2)*n^3 + n^2 - (1/2)*n.
Conjectures from Colin Barker, Jan 21 2019: (Start)
G.f.: 3*x*(4 + 29*x + 10*x^2 - 3*x^3) / (1 - x)^6.
a(n) = 6*a(n-1) - 15*a(n-2) + 20*a(n-3) - 15*a(n-4) + 6*a(n-5) - a(n-6) for n>6.
(End)
EXAMPLE
Some solutions for n=8:
..0. .0. .2. .0. .2. .2. .6. .6. .3. .5. .8. .1. .5. .4. .2. .0
..5. .5. .8. .1. .3. .5. .0. .3. .8. .6. .7. .2. .0. .2. .3. .8
..8. .3. .6. .1. .0. .1. .5. .6. .7. .6. .0. .3. .5. .5. .0. .1
..4. .0. .7. .0. .2. .5. .0. .5. .1. .7. .7. .4. .7. .6. .7. .8
..5. .7. .0. .5. .3. .4. .4. .2. .7. .5. .8. .7. .7. .8. .8. .1
CROSSREFS
Row 5 of A269409.
Sequence in context: A220225 A213376 A269642 * A347748 A226297 A286721
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 25 2016
STATUS
approved