A246744 Number of length 7+4 0..n arrays with no pair in any consecutive five terms totalling exactly n

2, 68, 10812, 135776, 2818830, 19906740, 162700376, 766650656, 3696053370, 13019727620, 45166073172, 128894476608, 358710268742, 876273071156, 2086036196400, 4529314688960, 9603337631346, 19024638124356, 36902088232940

Offset

1,1

Comments

Row 7 of A246737

Links

R. H. Hardin, Table of n, a(n) for n = 1..56

Formula

Empirical: a(n) = 3*a(n-1) +6*a(n-2) -26*a(n-3) -9*a(n-4) +99*a(n-5) -24*a(n-6) -216*a(n-7) +126*a(n-8) +294*a(n-9) -252*a(n-10) -252*a(n-11) +294*a(n-12) +126*a(n-13) -216*a(n-14) -24*a(n-15) +99*a(n-16) -9*a(n-17) -26*a(n-18) +6*a(n-19) +3*a(n-20) -a(n-21)

Example

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

Crossrefs

Sequence in context: A251793 A283038 A264457 * A362291 A364854 A041577

Adjacent sequences: A246741 A246742 A246743 * A246745 A246746 A246747

Keyword

nonn

Author

R. H. Hardin, Sep 02 2014

Status

approved