A203500 Number of nX2 0..6 arrays with every nonzero element less than or equal to some NW, E or S neighbor

1, 49, 1554, 29701, 481122, 7959529, 138035591, 2413093119, 41816203653, 721412975758, 12454301783794, 215270870681652, 3721658113926884, 64326398063727814, 1111713774851236084, 19213432056113523213

Offset

1,2

Comments

Column 2 of A203506

Links

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

Formula

Empirical: a(n) = 49*a(n-1) -1064*a(n-2) +14504*a(n-3) -139300*a(n-4) +974216*a(n-5) -5049458*a(n-6) +19784160*a(n-7) -59856834*a(n-8) +143372114*a(n-9) -282160674*a(n-10) +474196544*a(n-11) -679931029*a(n-12) +791307252*a(n-13) -707690496*a(n-14) +480221913*a(n-15) -265555686*a(n-16) +125326699*a(n-17) -42652674*a(n-18) +8555625*a(n-19)

Example

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

Crossrefs

Sequence in context: A032655 A001458 A004374 * A069327 A088068 A140394

Adjacent sequences: A203497 A203498 A203499 * A203501 A203502 A203503

Keyword

nonn

Author

R. H. Hardin Jan 02 2012

Status

approved