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A226439 Number of permutations of {1..n} with fewer than 6 interior elements having values lying between the values of their neighbors.

%I A226439 #8 Jul 17 2024 19:05:34
%S A226439 1,1,2,6,24,120,720,5040,40318,362370,3600306,38963958,453658380,
%T A226439 5626972260,73801171100,1017828597300,14699233982370,221584676368350,
%U A226439 3477976352489742,56725919426072106,959792584260031648,16822545496476258000,305055135390508456872
%N A226439 Number of permutations of {1..n} with fewer than 6 interior elements having values lying between the values of their neighbors.
%H A226439 Alois P. Heinz, <a href="/A226439/b226439.txt">Table of n, a(n) for n = 0..481</a> (terms n = 1..210 from R. H. Hardin)
%e A226439 Some solutions for n=7
%e A226439 ..2....1....6....2....2....6....5....2....6....5....1....2....6....4....5....5
%e A226439 ..1....2....3....7....3....5....3....5....3....6....7....7....1....7....1....4
%e A226439 ..6....7....4....3....4....7....6....6....2....7....4....6....4....1....2....7
%e A226439 ..5....4....2....5....7....2....4....4....5....1....3....3....3....2....7....2
%e A226439 ..7....3....5....4....1....3....2....1....4....4....6....5....5....6....6....3
%e A226439 ..4....5....1....1....5....4....1....3....1....3....2....4....2....5....4....6
%e A226439 ..3....6....7....6....6....1....7....7....7....2....5....1....7....3....3....1
%Y A226439 Column 6 of A226441.
%K A226439 nonn
%O A226439 0,3
%A A226439 _R. H. Hardin_, Jun 06 2013
%E A226439 a(0)=1 prepended by _Alois P. Heinz_, Jul 17 2024