A264132 Number of (1+1)X(n+1) arrays of permutations of 0..n*2+1 with each element having index change +-(.,.) 0,0 0,2 or 1,2.

1, 5, 25, 80, 256, 976, 3721, 13725, 50625, 189225, 707281, 2637376, 9834496, 36706880, 137007025, 511286105, 1908029761, 7120920301, 26575846441, 99181976400, 370150560000, 1381421480400, 5155538077561, 19240724018101

Offset

1,2

Comments

Row 1 of A264131.

Links

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

Formula

Empirical: a(n) = 4*a(n-1) -a(n-2) +15*a(n-4) -60*a(n-5) +15*a(n-6) -15*a(n-8) +60*a(n-9) -15*a(n-10) +a(n-12) -4*a(n-13) +a(n-14)

Example

Some solutions for n=4
..0..1..2..3..4....7..8..2..3..4....0..1..4..3..2....0..3..2..1..4
..7..8..5..6..9....5..6..0..1..9....5..8..7..6..9....5..6..9..8..7

Crossrefs

Cf. A264131.

Sequence in context: A238449 A062989 A122679 * A355949 A147114 A296669

Adjacent sequences: A264129 A264130 A264131 * A264133 A264134 A264135

Keyword

nonn

Author

R. H. Hardin, Nov 03 2015

Status

approved