A264258 Number of (2+1)X(n+1) arrays of permutations of 0..n*3+2 with each element having directed index change 0,1 0,-1 0,2 1,0 or -1,0.

9, 33, 157, 1124, 5468, 32361, 181644, 1005279, 5712287, 31908805, 179364032, 1008041332, 5656064297, 31779206260, 178441753729, 1002081327301, 5627883437261, 31604106229992, 177487167753036, 996741882957325

Offset

1,1

Comments

Row 2 of A264257.

Links

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

Formula

Empirical: a(n) = 2*a(n-1) +17*a(n-2) +43*a(n-3) -83*a(n-4) -228*a(n-5) -480*a(n-6) +71*a(n-7) +609*a(n-8) +2735*a(n-9) +2856*a(n-10) +3120*a(n-11) -2421*a(n-12) -9482*a(n-13) -15686*a(n-14) -15853*a(n-15) -3218*a(n-16) +19635*a(n-17) +34505*a(n-18) +38737*a(n-19) +6502*a(n-20) -13346*a(n-21) -42550*a(n-22) -21272*a(n-23) -15028*a(n-24) +21102*a(n-25) -1882*a(n-26) +11158*a(n-27) -14067*a(n-28) +12940*a(n-29) -3299*a(n-30) +12679*a(n-31) -7545*a(n-32) +3298*a(n-33) -5594*a(n-34) +2651*a(n-35) -1511*a(n-36) +1117*a(n-37) -692*a(n-38) +246*a(n-39) -165*a(n-40) +132*a(n-41) -10*a(n-42) +19*a(n-43) -16*a(n-44) -a(n-45) -a(n-46) +a(n-47)

Example

Some solutions for n=4
..5..2..1..4..9....1..6..7..4..3....1..6..3..4..2....1..2..0..4..3
..0..7..6..3.14....0.11..2..9..8....0..7.12..9..8...10..5..6..7.14
.11.10.13..8.12....5.12.10.14.13....5.10.11.14.13...11.12.13..8..9

Crossrefs

Cf. A264257.

Sequence in context: A140413 A097804 A146136 * A147444 A189179 A146445

Adjacent sequences: A264255 A264256 A264257 * A264259 A264260 A264261

Keyword

nonn

Author

R. H. Hardin, Nov 09 2015

Status

approved