A264019 Number of (4+1) X (n+1) arrays of permutations of 0..n*5+4 with each element having index change +-(.,.) 0,0 1,2 or 2,2.
1, 34, 1156, 20570, 366025, 7320500, 146410000, 2898918000, 57398576400, 1136955639600, 22520909184400, 446088564737200, 8836011280003600, 175021631355863600, 3466787272192723600, 68669304273355566000
Offset: 1
Keywords
Examples
Some solutions for n=4: ..7..8..2..3..4....7..8..9..3..4....7..8..2..3..4....0..1..2..3..4 ..5.13.19..1..9...17.13.19..1..2...17.13..0..1..9....5.13.14..8..9 .10.11..0..6.14...10.23..0..6.14...22.23.12..6.14...10.11.24..6..7 .15.23.24.18.12...22.16..5.18.12...15.16..5.18.19...15.16.17.18.19 .20.21.22.16.17...20.21.15.11.24...20.21.10.11.24...20.21.22.23.12
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Crossrefs
Row 4 of A264017.
Formula
Empirical: a(n) = 19*a(n-1) + 304*a(n-3) + 256*a(n-4) for n>8.
Empirical g.f.: x*(1 + 15*x + 510*x^2 - 1698*x^3 - 35397*x^4 + 5897*x^5 + 771284*x^6 + 590480*x^7) / ((1 + 16*x^2)*(1 - 19*x - 16*x^2)). - Colin Barker, Jan 03 2019