cp's OEIS Frontend

A264670 Number of (n+1) X (2+1) arrays of permutations of 0..n*3+2 with each element having directed index change -1,-1 1,0 -1,-2 -2,-2 or 0,1.

%I A264670 #7 Jan 08 2019 15:18:59
%S A264670 1,2,9,19,44,108,264,649,1573,3837,9353,22801,55571,135432,330113,
%T A264670 804604,1961113,4779902,11650318,28396001,69211142,168692149,
%U A264670 411162676,1002149647,2442594935,5953472042,14510727488,35367800720,86203902041
%N A264670 Number of (n+1) X (2+1) arrays of permutations of 0..n*3+2 with each element having directed index change -1,-1 1,0 -1,-2 -2,-2 or 0,1.
%H A264670 R. H. Hardin, <a href="/A264670/b264670.txt">Table of n, a(n) for n = 1..210</a>
%F A264670 Empirical: a(n) = 2*a(n-1) + a(n-3) + 3*a(n-4) + 2*a(n-5) - a(n-6) + 4*a(n-7) - a(n-8) - a(n-10).
%F A264670 Empirical g.f.: x*(1 + 5*x^2 + x^4 + 3*x^5 - x^6 - x^8) / (1 - 2*x - x^3 - 3*x^4 - 2*x^5 + x^6 - 4*x^7 + x^8 + x^10). - _Colin Barker_, Jan 08 2019
%e A264670 Some solutions for n=4:
%e A264670 ..5..0..1....4..0..1....5..0..1....4..0..1....4..0..1....5..0..1....8..0..1
%e A264670 .11..3..2...11..8..2....8..3..2....8..3..2....7..8..2...11..8..2...11..3..2
%e A264670 .10..4..7....3..6..5...11..4..7...14.11..5....3..6..5....3..4..7...14..4..5
%e A264670 ..6.14..8...14..7.10....6.14.10....6..7.10...13.14.10....6.14.10....6..7.10
%e A264670 ..9.12.13....9.12.13....9.12.13....9.12.13....9.12.11....9.12.13....9.12.13
%Y A264670 Column 2 of A264676.
%K A264670 nonn
%O A264670 1,2
%A A264670 _R. H. Hardin_, Nov 20 2015