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A264418
Number of (n+1)X(3+1) arrays of permutations of 0..n*4+3 with each element having directed index change 0,1 2,2 1,0 -1,2 -2,-1 or -1,-1.
1
0, 12, 96, 529, 4843, 44264, 352713, 2840274, 23795758, 197390196, 1619132059, 13345740560, 110326933611, 910298134238, 7505842151352, 61932503872184, 511075503235669, 4216464623838747, 34786555887673881, 287016646384919794
OFFSET
1,2
COMMENTS
Column 3 of A264422.
FORMULA
Empirical recurrence of order 70 (see link above)
EXAMPLE
Some solutions for n=4
..9..6..1..5....5.10..1..2....5..6..7..2....9..6..7..5....9.10..4..2
.13.10..2..3....0..4.15..3...13..1.15..3....0..1..2..3....0..1..5..3
..4.14..0..7...13.14..6..7....4.14..0.10...13.14.19.10...13.14..6..7
.17.18.19.11....8.18.19.11...17..9.19.11...17.18..4.11....8.18.19.11
.12.16..8.15...12.16.17..9...12.16..8.18...12.16..8.15...12.16.17.15
CROSSREFS
Cf. A264422.
Sequence in context: A120658 A121627 A138162 * A073392 A038845 A204623
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 12 2015
STATUS
approved