A263905 T(n,k)=Number of length n arrays of permutations of 0..n-1 with each element moved by -k to k places and the total absolute value of displacements not greater than 2*(n-1).
1, 1, 2, 1, 2, 3, 1, 2, 6, 5, 1, 2, 6, 13, 8, 1, 2, 6, 20, 31, 13, 1, 2, 6, 20, 61, 73, 21, 1, 2, 6, 20, 76, 185, 172, 34, 1, 2, 6, 20, 76, 269, 577, 399, 55, 1, 2, 6, 20, 76, 300, 979, 1788, 932, 89, 1, 2, 6, 20, 76, 300, 1189, 3552, 5540, 2177, 144, 1, 2, 6, 20, 76, 300, 1252
Offset: 1
Examples
Some solutions for n=7 k=4 ..3....0....3....2....4....0....3....0....0....1....4....0....3....0....2....1 ..0....3....1....1....1....1....1....5....1....3....0....2....0....2....1....3 ..2....1....5....5....0....3....0....3....4....2....2....1....4....4....4....2 ..6....4....2....0....3....2....6....4....5....6....1....5....2....1....0....6 ..1....5....0....3....6....4....4....1....6....0....5....6....5....3....6....0 ..4....6....4....4....2....5....2....2....2....4....6....4....1....6....5....5 ..5....2....6....6....5....6....5....6....3....5....3....3....6....5....3....4
Links
- R. H. Hardin, Table of n, a(n) for n = 1..617
Crossrefs
Column 1 is A000045(n+1).
Formula
Empirical for column k:
k=1: a(n) = a(n-1) +a(n-2)
k=2: a(n) = 2*a(n-1) +2*a(n-3) +a(n-4) -3*a(n-5) -2*a(n-7) +a(n-9)
Comments