A250349 Number of length n arrays x(i), i=1..n with x(i) in i..i+6 and no value appearing more than 2 times

7, 49, 338, 2287, 15186, 99344, 644040, 4164930, 26882466, 173276640, 1115910270, 7182799173, 46220503936, 297376327082, 1913081363032, 12306454081360, 79161863609011, 509201240096045, 3275346169991511, 21067913854706817

Offset

1,1

Comments

Column 6 of A250351

Links

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

Formula

Empirical: a(n) = 7*a(n-1) -12*a(n-3) -32*a(n-4) -101*a(n-5) -623*a(n-6) -3703*a(n-7) +2630*a(n-8) +10358*a(n-9) +15805*a(n-10) +19448*a(n-11) +41930*a(n-12) +17560*a(n-13) -133023*a(n-14) -179079*a(n-15) -42337*a(n-16) +101951*a(n-17) -34974*a(n-18) -21497*a(n-19) +198775*a(n-20) +430980*a(n-21) +205427*a(n-22) -195761*a(n-23) -191518*a(n-24) -100666*a(n-25) -82593*a(n-26) -182721*a(n-27) -26175*a(n-28) +61736*a(n-29) +73291*a(n-30) +56839*a(n-31) -14702*a(n-32) -18860*a(n-33) -26635*a(n-34) -3079*a(n-35) +4310*a(n-36) +5890*a(n-37) -1330*a(n-38) -882*a(n-39) +37*a(n-40) -321*a(n-41) -191*a(n-42) +119*a(n-43) +25*a(n-44) -9*a(n-45) -a(n-46) -a(n-48)

Example

Some solutions for n=6
..1....2....2....1....0....1....4....2....3....4....3....1....2....2....0....4
..4....3....4....1....3....1....5....7....2....7....5....3....2....2....6....7
..8....3....7....3....5....5....2....4....5....3....6....4....7....4....2....3
..7....9....7....8....5....7....9....6....9....4....7....5....5....4....6....9
.10....7....6....4...10....9...10....4....6....8...10....9....8....6....7....6
..8....8...10....5....6....9....5...11....6....9....8....8....5....8....8....9

Crossrefs

Sequence in context: A268455 A323559 A366925 * A171281 A328086 A216129

Adjacent sequences: A250346 A250347 A250348 * A250350 A250351 A250352

Keyword

nonn

Author

R. H. Hardin, Nov 19 2014

Status

approved