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A264295
Number of (n+1)X(3+1) arrays of permutations of 0..n*4+3 with each element having directed index change 0,1 0,-2 1,0 or -1,0.
1
5, 8, 89, 192, 1413, 4352, 24781, 90112, 449665, 1781256, 8340733, 34594368, 156594265, 665254400, 2958805225, 12729812160, 56099851853, 242965239816, 1065598885233, 4631110326400, 20260075655037, 88211124098304
OFFSET
1,1
COMMENTS
Column 3 of A264299.
LINKS
FORMULA
Empirical: a(n) = 5*a(n-1) +2*a(n-2) -34*a(n-3) +79*a(n-4) -103*a(n-5) +60*a(n-6) -220*a(n-7) +610*a(n-8) -142*a(n-9) -1276*a(n-10) +1276*a(n-11) +142*a(n-12) -610*a(n-13) +220*a(n-14) -60*a(n-15) +103*a(n-16) -79*a(n-17) +34*a(n-18) -2*a(n-19) -5*a(n-20) +a(n-21)
EXAMPLE
Some solutions for n=4
..4..0..1..2....4..5..1..2....2..0..1..7....2..3..1..7....2..0..1..7
..8..9..5..3....0..9.10..3....6..4..5..3....0..9..5.11....8..9..5..3
.12.13..6..7...12.11..6..7...12..8.14.10....4..8..6.15....4.13..6.10
.16.17.10.11....8.17.13.19...16..9.13.11...16.17.10.19...16.17.18.11
.18.19.14.15...18.16.14.15...18.19.17.15...12.13.14.18...12.19.14.15
CROSSREFS
Cf. A264299.
Sequence in context: A153720 A372124 A101016 * A025518 A361225 A356826
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 11 2015
STATUS
approved