login
A264196
Number of (2+1)X(n+1) arrays of permutations of 0..n*3+2 with each element having index change +-(.,.) 0,0 0,2 or 2,1.
1
2, 18, 180, 864, 4608, 29040, 184525, 1089000, 6480000, 39335400, 238918849, 1439151168, 8674025472, 52415185536, 316746710820, 1912128349230, 11543580054050, 69713595928295, 421013268028981, 2542224621830400
OFFSET
1,1
COMMENTS
Row 2 of A264195.
LINKS
FORMULA
Empirical: a(n) = 4*a(n-1) -a(n-2) +52*a(n-3) +300*a(n-4) -532*a(n-5) +119*a(n-6) -6244*a(n-7) -24121*a(n-8) +16320*a(n-9) -2400*a(n-10) +131520*a(n-11) +471143*a(n-12) -200732*a(n-13) +14903*a(n-14) -916076*a(n-15) -3182100*a(n-16) +1079756*a(n-17) -26017*a(n-18) +2328572*a(n-19) +7880063*a(n-20) -2432640*a(n-21) -2432640*a(n-23) -7880063*a(n-24) +2328572*a(n-25) +26017*a(n-26) +1079756*a(n-27) +3182100*a(n-28) -916076*a(n-29) -14903*a(n-30) -200732*a(n-31) -471143*a(n-32) +131520*a(n-33) +2400*a(n-34) +16320*a(n-35) +24121*a(n-36) -6244*a(n-37) -119*a(n-38) -532*a(n-39) -300*a(n-40) +52*a(n-41) +a(n-42) +4*a(n-43) +a(n-44)
EXAMPLE
Some solutions for n=4
.11..3.13..1..4....0..1..4.14..2....0..1..2.14..4....0..1..4.14..2
..7..6..5..8..9....5..8..7..6..9....5..8..7..6..9....5..6..9..8..7
.10..0.14..2.12...12.11.10.13..3...12.13.10.11..3...10.13.12.11..3
CROSSREFS
Cf. A264195.
Sequence in context: A318218 A073558 A132306 * A214768 A337855 A099044
KEYWORD
nonn
AUTHOR
R. H. Hardin, Nov 07 2015
STATUS
approved