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 A217887 Number of n element 1..n arrays with each element the minimum of 4 adjacent elements of a permutation of 1..n+3 of n+3 elements 0
 1, 3, 11, 45, 196, 898, 4272, 21002, 106564, 558780, 3037926, 17203726, 101981944, 635338608 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Column 4 of A217891 LINKS Table of n, a(n) for n=1..14. EXAMPLE Some solutions for n=4 ..1....4....1....2....2....1....1....1....3....4....3....1....4....1....1....1 ..3....1....4....2....2....2....2....1....3....3....2....1....2....1....3....3 ..2....1....2....1....3....4....2....3....1....1....2....2....1....1....3....4 ..2....1....2....1....1....3....2....3....1....1....1....4....1....3....2....2 CROSSREFS Sequence in context: A049172 A049155 A063024 * A151129 A151130 A216949 Adjacent sequences: A217884 A217885 A217886 * A217888 A217889 A217890 KEYWORD nonn AUTHOR R. H. Hardin Oct 14 2012 STATUS approved

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Last modified November 29 10:53 EST 2023. Contains 367429 sequences. (Running on oeis4.)