This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A250381 Number of length n+3 0..2 arrays with no four consecutive terms having the maximum of any two terms equal to the minimum of the remaining two terms. 1
 42, 78, 146, 274, 514, 966, 1816, 3414, 6418, 12066, 22688, 42658, 80208, 150808, 283566, 533182, 1002538, 1885048, 3544452, 6664608, 12531430, 23562750, 44304934, 83306386, 156640636, 294530672, 553804746, 1041316906, 1957983912 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Column 2 of A250387. LINKS R. H. Hardin, Table of n, a(n) for n = 1..210 FORMULA From Colin Barker, Aug 20 2017: (Start) Empirical recurrence: a(n) = a(n-1) +2*a(n-2) -a(n-3) +3*a(n-4) -a(n-5) -7*a(n-6) +a(n-7) +a(n-10). Empirical g.f.: 2*x*(21 + 18*x - 8*x^2 + 7*x^3 - 50*x^4 - 71*x^5 + 15*x^6 + 4*x^7 + 7*x^8 + 12*x^9) / (1 - x - 2*x^2 + x^3 - 3*x^4 + x^5 + 7*x^6 - x^7 - x^10). (End) EXAMPLE Some solutions for n=6 ..1....1....2....2....1....0....2....1....0....0....1....0....1....0....2....1 ..0....2....0....0....0....0....1....2....1....2....0....2....0....1....0....0 ..0....2....1....2....1....1....2....2....2....1....2....2....2....0....0....2 ..2....1....2....0....0....2....0....0....0....0....0....1....0....1....1....0 ..2....0....0....1....1....2....2....1....2....2....2....0....1....0....1....2 ..0....2....2....0....0....1....1....2....1....2....0....2....2....1....0....1 ..1....2....1....2....2....0....2....0....0....1....1....0....0....0....0....0 ..2....0....2....2....0....2....1....0....2....0....2....2....0....2....1....2 ..2....1....1....0....2....2....2....2....0....2....2....0....2....2....1....0 CROSSREFS Sequence in context: A068700 A303283 A135850 * A153644 A172437 A160283 Adjacent sequences:  A250378 A250379 A250380 * A250382 A250383 A250384 KEYWORD nonn AUTHOR R. H. Hardin, Nov 20 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 | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 5 13:26 EST 2019. Contains 329751 sequences. (Running on oeis4.)