A245136 Number of length 6 0..n arrays least squares fitting to a zero slope straight line, with a single point taken as having zero slope

8, 43, 172, 505, 1248, 2687, 5220, 9385, 15868, 25539, 39428, 58805, 85144, 120163, 165900, 224593, 298832, 391539, 505928, 645645, 814656, 1017335, 1258484, 1543341, 1877624, 2267451, 2719516, 3240965, 3839476, 4523383, 5301420, 6183009

Offset

1,1

Comments

Row 6 of A245134

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-1) -a(n-2) +2*a(n-3) -4*a(n-4) +4*a(n-5) -5*a(n-6) +4*a(n-7) -5*a(n-8) +8*a(n-9) -5*a(n-10) +4*a(n-11) -5*a(n-12) +4*a(n-13) -4*a(n-14) +2*a(n-15) -a(n-16) +2*a(n-17) -a(n-18).

Empirical: G.f.: -x*(-8 -27*x -94*x^2 -188*x^3 -356*x^4 -492*x^5 -640*x^6 -651*x^7 -644*x^8 -492*x^9 -356*x^10 -187*x^11 -96*x^12 -24*x^13 -8*x^14 -2*x^16 +x^17) ) / ( (1+x+x^2)^2*(x^4+x^3+x^2+x+1)^2*(x-1)^6 ). - R. J. Mathar, Jul 12 2014

Example

Some solutions for n=10
..7....9....8....6....7....7....6....3....3....0....0....3....4....2....2....6
.10....0....3....2....9....9...10....0....6....9....6....0....7....4....7....4
..2....8....2....9....7...10....3....4....8....1....9....6....0....1...10....9
..8....3....3...10....2....4....0....0....6....8....0....1....5....0....4....0
..3...10....1....0....9....6....6....3...10....5....9....5....2....1....4....2
.10....4....9....7....8...10....9....2....1....1....0....1....6....4....5....9

Crossrefs

Sequence in context: A025064 A241695 A224037 * A362904 A036424 A036633

Adjacent sequences: A245133 A245134 A245135 * A245137 A245138 A245139

Keyword

nonn

Author

R. H. Hardin, Jul 12 2014

Status

approved