A211841 Number of nonnegative integer arrays of length n+8 with new values 0 upwards introduced in order, no three adjacent elements equal, and containing the value n+1

16479, 86295, 426022, 1874580, 7251376, 24849643, 76514893, 214762865, 556551660, 1346075734, 3065835607, 6624907961, 13666568938, 27055113275, 51624909857, 95304639221, 170767632249, 297806806741, 506691598400

Offset

1,1

Comments

Row 7 of A211836

Links

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

Formula

Empirical: a(n) = (1/46080)*n^12 + (5/4608)*n^11 + (1133/46080)*n^10 + (69091/207360)*n^9 + (139007/46080)*n^8 + (9401159/483840)*n^7 + (4294903/46080)*n^6 + (23903551/69120)*n^5 + (3910501/3840)*n^4 + (123369071/51840)*n^3 + (677503/160)*n^2 + (6491021/1260)*n + 3233

Example

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

Crossrefs

Sequence in context: A057680 A157796 A186848 * A234054 A234055 A234047

Adjacent sequences: A211838 A211839 A211840 * A211842 A211843 A211844

Keyword

nonn

Author

R. H. Hardin Apr 21 2012

Status

approved