A250360 Number of length n arrays x(i), i=1..n with x(i) in i..i+7 and no value appearing more than 3 times

8, 64, 512, 4091, 32608, 259106, 2052904, 16234706, 128373416, 1015004124, 8024737888, 63441430784, 501536079048, 3964832287906, 31343315384096, 247778886499164, 1958768810680376, 15484663643904612, 122410935014171288

Offset

1,1

Comments

Column 7 of A250361

Links

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

Formula

Empirical: a(n) = 8*a(n-1) -16*a(n-4) -64*a(n-5) -488*a(n-6) -3752*a(n-7) -29038*a(n-8) +1592*a(n-9) +11770*a(n-10) +66616*a(n-11) +151100*a(n-12) +472248*a(n-13) +953904*a(n-14) +183480*a(n-15) -568091*a(n-16) -1229632*a(n-17) -708460*a(n-18) -48256*a(n-19) +682669*a(n-20) -62120*a(n-21) +527060*a(n-22) +1075872*a(n-23) +1391771*a(n-24) +726760*a(n-25) +633398*a(n-26) +879696*a(n-27) +723511*a(n-28) -757912*a(n-29) -103140*a(n-30) +79256*a(n-31) +602486*a(n-32) -304224*a(n-33) -111134*a(n-34) -350584*a(n-35) +418679*a(n-36) -76624*a(n-37) +104514*a(n-38) -256568*a(n-39) +138277*a(n-40) -37600*a(n-41) +136030*a(n-42) -105232*a(n-43) +18365*a(n-44) -15688*a(n-45) +34876*a(n-46) -16992*a(n-47) -905*a(n-48) -4336*a(n-49) -24*a(n-50) -1968*a(n-52) -192*a(n-53) +12*a(n-56)

Example

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

Crossrefs

Sequence in context: A269493 A269775 A269655 * A190130 A125908 A206454

Adjacent sequences: A250357 A250358 A250359 * A250361 A250362 A250363

Keyword

nonn

Author

R. H. Hardin, Nov 19 2014

Status

approved