The OEIS is supported by the many generous donors to the OEIS Foundation.

 Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 60th year, we have over 367,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”). Other ways to Give
 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A250364 Number of length 6 arrays x(i), i=1..6 with x(i) in i..i+n and no value appearing more than 3 times. 1
 64, 729, 4048, 15365, 45866, 115963, 259106, 526505, 992530, 1760831, 2971178, 4807021, 7503770, 11357795, 16736146, 24086993, 33950786, 46972135, 63912410, 85663061, 113259658, 147896651, 190942850, 243957625, 308707826, 387185423 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA Empirical: a(n) = n^6 + 6*n^5 + 15*n^4 + 5*n^3 + 57*n^2 + 13*n + 1 for n>3. Conjectures from Colin Barker, Nov 13 2018: (Start) G.f.: x*(64 + 281*x + 289*x^2 + 98*x^3 + 44*x^4 + 57*x^5 - 405*x^6 + 482*x^7 - 232*x^8 + 42*x^9) / (1 - x)^7. a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n>10. (End) EXAMPLE Some solutions for n=6: ..2....1....5....4....5....4....1....0....0....1....5....4....5....5....0....4 ..2....6....4....7....2....6....4....1....1....5....5....4....1....3....4....4 ..3....8....6....7....2....7....6....3....7....4....8....8....6....2....7....7 ..8....7....4....5....7....7....8....5....5....4....8....8....8....9....9....7 ..8....7....4....5....4....7....4....9....8....8....4....9....6....8....4....8 ..7...11....7...10....7....8....8....6....5....6...10....7....9....6....7....8 CROSSREFS Row 6 of A250361. Sequence in context: A223953 A224137 A016899 * A346638 A017676 A055015 Adjacent sequences: A250361 A250362 A250363 * A250365 A250366 A250367 KEYWORD nonn AUTHOR R. H. Hardin, Nov 19 2014 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 9 04:08 EST 2023. Contains 367681 sequences. (Running on oeis4.)