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A251422 Number of length n+2 0..2 arrays with the sum of the maximum minus twice the median plus the minimum of adjacent triples multiplied by some arrangement of +-1 equal to zero.

%I A251422 #6 Jul 23 2025 13:19:39
%S A251422 9,41,97,341,1003,3129,9439,28717,86695,261789,788373,2372693,7133179,
%T A251422 21434717,64377579,193296317,580236633,1741470477,5226041293,
%U A251422 15681654949,47052540983,141173946441,423556852705,1270745764685,3812398439683
%N A251422 Number of length n+2 0..2 arrays with the sum of the maximum minus twice the median plus the minimum of adjacent triples multiplied by some arrangement of +-1 equal to zero.
%C A251422 Column 2 of A251428
%H A251422 R. H. Hardin, <a href="/A251422/b251422.txt">Table of n, a(n) for n = 1..210</a>
%F A251422 Empirical: a(n) = 8*a(n-1) -21*a(n-2) +12*a(n-3) +36*a(n-4) -66*a(n-5) +25*a(n-6) +56*a(n-7) -58*a(n-8) -56*a(n-9) +63*a(n-10) +8*a(n-11) +54*a(n-12) -80*a(n-13) +24*a(n-14)
%e A251422 Some solutions for n=9
%e A251422 ..1....2....1....1....2....0....0....0....1....2....1....1....2....0....2....0
%e A251422 ..0....2....1....1....0....1....0....2....0....1....1....2....2....1....1....1
%e A251422 ..0....0....2....0....2....0....2....0....0....1....1....2....0....0....1....2
%e A251422 ..1....0....1....2....0....2....1....1....2....1....2....1....1....0....1....0
%e A251422 ..2....0....1....1....1....0....2....2....0....2....1....1....1....2....1....1
%e A251422 ..2....1....0....0....2....1....1....2....0....1....1....1....2....2....0....2
%e A251422 ..2....1....2....1....1....1....2....2....0....2....2....2....1....0....1....0
%e A251422 ..1....2....2....2....1....0....1....2....2....0....1....0....1....1....0....1
%e A251422 ..1....1....2....0....0....0....1....1....1....2....0....0....1....2....1....1
%e A251422 ..1....2....2....0....1....2....1....1....1....0....0....0....0....1....2....0
%e A251422 ..2....1....2....2....2....2....2....0....1....2....0....2....1....2....2....2
%K A251422 nonn
%O A251422 1,1
%A A251422 _R. H. Hardin_, Dec 02 2014