A200156 Number of 0..n arrays x(0..4) of 5 elements with zero 4th difference.

2, 15, 40, 103, 202, 381, 636, 1033, 1550, 2287, 3212, 4451, 5946, 7869, 10140, 12969, 16238, 20211, 24744, 30147, 36222, 43349, 51296, 60493, 70646, 82267, 95016, 109467, 125206, 142897, 162076, 183477, 206546, 232123, 259596, 289879, 322262

Offset

1,1

Comments

Row 5 of A200154.

Links

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

Formula

Empirical: a(n) = a(n-1) +a(n-2) +a(n-4) -3*a(n-5) -a(n-6) +a(n-8) +3*a(n-9) -a(n-10) -a(n-12) -a(n-13) +a(n-14).

Empirical g.f.: x*(2 + 13*x + 23*x^2 + 48*x^3 + 57*x^4 + 67*x^5 + 60*x^6 + 48*x^7 + 26*x^8 + 11*x^9 + x^10 - x^12 + x^13) / ((1 - x)^5*(1 + x)^3*(1 + x^2)^2*(1 + x + x^2)). - Colin Barker, May 17 2018

Example

Some solutions for n=6:
..6....4....1....0....2....6....2....2....4....6....6....0....6....6....2....4
..4....5....1....6....0....1....2....3....6....2....5....6....6....5....3....4
..1....3....1....6....2....0....0....2....3....0....2....6....4....4....2....5
..0....1....2....4....4....2....0....1....0....0....1....3....3....4....2....5
..4....2....5....4....2....6....6....2....2....2....6....0....6....6....6....2

Crossrefs

Cf. A200154.

Sequence in context: A070009 A070170 A033568 * A249997 A032016 A254856

Adjacent sequences: A200153 A200154 A200155 * A200157 A200158 A200159

Keyword

nonn

Author

R. H. Hardin, Nov 13 2011

Status

approved