cp's OEIS Frontend

A250641 Number of length n+1 0..3 arrays with the sum of the maximum of each adjacent pair multiplied by some arrangement of +-1 equal to zero.

%I A250641 #6 Jul 23 2025 12:38:25
%S A250641 1,36,44,476,1424,7696,28238,126482,491943,2059700,8161068,33268124,
%T A250641 132637221,534771362,2136620867,8574987528,34285733053,137334914170,
%U A250641 549255340746,2198311980408,8792729559738,35179581032056,140715004320059
%N A250641 Number of length n+1 0..3 arrays with the sum of the maximum of each adjacent pair multiplied by some arrangement of +-1 equal to zero.
%C A250641 Column 3 of A250646
%H A250641 R. H. Hardin, <a href="/A250641/b250641.txt">Table of n, a(n) for n = 1..187</a>
%F A250641 Empirical: a(n) = 11*a(n-1) -22*a(n-2) -172*a(n-3) +787*a(n-4) +353*a(n-5) -7413*a(n-6) +8289*a(n-7) +29140*a(n-8) -67796*a(n-9) -32276*a(n-10) +217716*a(n-11) -108368*a(n-12) -314968*a(n-13) +384528*a(n-14) +123824*a(n-15) -451104*a(n-16) +169760*a(n-17) +185424*a(n-18) -183216*a(n-19) +24640*a(n-20) +40064*a(n-21) -24448*a(n-22) +5760*a(n-23) -512*a(n-24) for n>25
%e A250641 Some solutions for n=6
%e A250641 ..0....0....3....2....0....1....2....2....3....0....1....3....3....0....1....0
%e A250641 ..2....3....2....3....0....0....3....2....1....3....2....2....1....3....1....1
%e A250641 ..1....2....1....2....3....1....1....3....3....1....1....3....1....3....1....2
%e A250641 ..2....2....1....0....0....1....0....2....3....3....1....0....1....1....3....0
%e A250641 ..0....2....2....2....2....1....2....1....2....1....0....1....2....2....1....2
%e A250641 ..2....0....3....2....2....3....1....3....1....3....1....1....1....0....0....1
%e A250641 ..2....0....1....1....0....1....1....2....2....1....0....3....0....3....3....1
%K A250641 nonn
%O A250641 1,2
%A A250641 _R. H. Hardin_, Nov 26 2014