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A264515 Number of (n+1)X(3+1) arrays of permutations of 0..n*4+3 with each element having directed index change -1,0 0,2 -1,-2 or 1,0. 1

%I

%S 1,1,9,36,144,576,2116,8281,31329,121801,467856,1809025,6969600,

%T 26884225,103632400,399560121,1540484001,5939322489,22899558276,

%U 88289802496,340406901136,1312449766884,5060209759081,19509827162049,75220946346001

%N Number of (n+1)X(3+1) arrays of permutations of 0..n*4+3 with each element having directed index change -1,0 0,2 -1,-2 or 1,0.

%C Column 3 of A264520.

%H R. H. Hardin, <a href="/A264515/b264515.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +7*a(n-2) -17*a(n-3) -5*a(n-4) +60*a(n-5) +8*a(n-6) -24*a(n-7) -36*a(n-8) +36*a(n-11) +24*a(n-12) -8*a(n-13) -60*a(n-14) +5*a(n-15) +17*a(n-16) -7*a(n-17) -3*a(n-18) +a(n-19)

%e Some solutions for n=4

%e ..4..5..0..7....4..5..0..1....4..5..6..7....6..5..0..1....4..7..0..1

%e ..8..1..2..3....8.11..2..3....0..1..2..3...10.11..2..3...10.11..2..3

%e .14.15..6..9...14.15..6..7...14.15..8..9....4.15..8..7...14..5..6..9

%e .18.19.10.11...18..9.10.19...18.19.10.11...16..9.18.19....8.17.18.19

%e .12.13.16.17...12.13.16.17...12.13.16.17...12.13.14.17...12.13.16.15

%Y Cf. A264520.

%K nonn

%O 1,3

%A _R. H. Hardin_, Nov 16 2015

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Last modified June 19 14:40 EDT 2021. Contains 345140 sequences. (Running on oeis4.)