1,1

Row 4 of A200272.

R. H. Hardin, Table of n, a(n) for n = 1..200

Empirical: a(n) = a(n-3) +a(n-5) +a(n-6) -a(n-8) -a(n-9) +a(n-10) -a(n-11) -a(n-13) +a(n-14) -a(n-15) -a(n-16) +a(n-18) +a(n-19) +a(n-21) -a(n-24).

Empirical g.f.: x*(2 + 3*x + 6*x^2 + 7*x^3 + 11*x^4 + 17*x^5 + 22*x^6 + 24*x^7 + 26*x^8 + 33*x^9 + 31*x^10 + 32*x^11 + 26*x^12 + 26*x^13 + 21*x^14 + 15*x^15 + 10*x^16 + 8*x^17 + 6*x^18 + 3*x^19 + 3*x^20 + x^21 - x^23) / ((1 - x)^4*(1 + x)^2*(1 - x + x^2)*(1 + x + x^2)^2*(1 - x + x^2 - x^3 + x^4)*(1 + x + x^2 + x^3 + x^4)^2). - Colin Barker, May 20 2018

Some solutions for n=6:

..2....3....0....6....3....5....0....4....1....5....0....5....5....3....0....4

..2....5....0....5....1....4....2....4....1....3....3....6....5....3....4....2

..2....6....0....4....0....3....3....4....1....2....5....6....5....3....6....1

..2....6....0....3....0....2....3....4....1....2....6....5....5....3....6....1

..2....5....0....2....1....1....2....4....1....3....6....3....5....3....4....2

..2....3....0....1....3....0....0....4....1....5....5....0....5....3....0....4

Cf. A200272.

Sequence in context: A146937 A032231 A389472 * A303664 A190276 A113808

Adjacent sequences: A200270 A200271 A200272 * A200274 A200275 A200276

R. H. Hardin, Nov 15 2011

approved