A269408 Number of length-n 0..7 arrays with no repeated value greater than or equal to the previous repeated value.

8, 64, 504, 3948, 30744, 238224, 1837752, 14121282, 108123624, 825227424, 6279994728, 47663522844, 360868232424, 2726022470928, 20549497120776, 154606709405835, 1161096042133440, 8705061811230400, 65160664171875440

Offset

1,1

Comments

Column 7 of A269409.

Links

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

Formula

Empirical: a(n) = 56*a(n-1) -1344*a(n-2) +17752*a(n-3) -135716*a(n-4) +545496*a(n-5) -463792*a(n-6) -4675336*a(n-7) +12240018*a(n-8) +21847336*a(n-9) -72913568*a(n-10) -123833976*a(n-11) +152002508*a(n-12) +520479176*a(n-13) +513890832*a(n-14) +230592040*a(n-15) +40353607*a(n-16)

Example

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

Crossrefs

Cf. A269409.

Sequence in context: A269639 A269536 A269677 * A269605 A269466 A127426

Adjacent sequences: A269405 A269406 A269407 * A269409 A269410 A269411

Keyword

nonn

Author

R. H. Hardin, Feb 25 2016

Status

approved