A250359 Number of length n arrays x(i), i=1..n with x(i) in i..i+6 and no value appearing more than 3 times

7, 49, 343, 2397, 16700, 115963, 803382, 5565230, 38548644, 266998350, 1849229664, 12807494729, 88702171850, 614332682800, 4254735401463, 29467361754942, 204084413284570, 1413443236278923, 9789192962198232, 67797768520165387

Offset

1,1

Comments

Column 6 of A250361

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -8*a(n-4) -40*a(n-5) -265*a(n-6) -1800*a(n-7) +38*a(n-8) +336*a(n-9) +1937*a(n-10) +3833*a(n-11) +6318*a(n-12) +303*a(n-13) -1245*a(n-14) -3056*a(n-15) -1258*a(n-16) +725*a(n-17) +1024*a(n-18) +343*a(n-19) +34*a(n-20) -137*a(n-21) -77*a(n-22) +47*a(n-24) +14*a(n-25)

Example

Some solutions for n=6
..1....3....5....1....1....1....1....0....4....1....2....4....5....3....2....2
..1....4....2....2....6....7....3....6....7....7....1....6....6....6....5....1
..7....8....7....7....4....3....2....6....3....4....8....8....8....7....7....5
..4....3....4....7....3....5....6....8....8....4....4....7....6....3....4....7
..7....7....7....6....9....7....7....5...10....4....4....4....7....9....5...10
..7....9....5....6....6....8....6....7....8....6....7....5....9....6....7....8

Crossrefs

Sequence in context: A269492 A269774 A269654 * A045584 A228439 A216130

Adjacent sequences: A250356 A250357 A250358 * A250360 A250361 A250362

Keyword

nonn

Author

R. H. Hardin, Nov 19 2014

Status

approved