A264671 Number of (n+1)X(3+1) arrays of permutations of 0..n*4+3 with each element having directed index change -1,-1 1,0 -1,-2 -2,-2 or 0,1.

1, 10, 34, 145, 603, 2417, 9976, 40825, 166985, 684253, 2801318, 11470702, 46972259, 192337615, 787587465, 3225016272, 13205769817, 54075000313, 221426203265, 906695582830, 3712735776142, 15202904012125, 62252826121583

Offset

1,2

Comments

Column 3 of A264676.

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 2*a(n-1) +6*a(n-2) +10*a(n-3) +6*a(n-5) +11*a(n-6) +4*a(n-7) +22*a(n-8) +21*a(n-9) -4*a(n-10) -10*a(n-11) -10*a(n-12) -2*a(n-13) +a(n-15)

Example

Some solutions for n=4
..6..7..1..2....6..0..1..2....5..0..1..2....5..0..1..2....6..0..1..2
..0..4..5..3...10..4..5..3...10..4.11..3....9..4.11..3...14.10..5..3
.13..8.15.10...13.14.15..7...13.15..6..7...13.15..6..7....4.15..9..7
.17..9.19.11....8..9.19.11....8..9.19.14....8.19.10.14....8.19.13.11
.12.16.14.18...12.16.17.18...12.16.17.18...12.16.17.18...12.16.17.18

Crossrefs

Cf. A264676.

Sequence in context: A068078 A067806 A001446 * A341300 A232902 A001890

Adjacent sequences: A264668 A264669 A264670 * A264672 A264673 A264674

Keyword

nonn

Author

R. H. Hardin, Nov 20 2015

Status

approved