login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A264629 Number of (2+1) X (n+1) arrays of permutations of 0..n*3+2 with each element having directed index change -2,0 -1,0 0,-1 or 1,1. 1
1, 2, 4, 9, 16, 37, 76, 160, 337, 704, 1485, 3110, 6532, 13713, 28784, 60441, 126872, 266368, 559201, 1173968, 2464617, 5174122, 10862468, 22804377, 47874976, 100507613, 211003236, 442975264, 929971633, 1952360368, 4098738901 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) + 2*a(n-5) - 2*a(n-6) + 4*a(n-7) - a(n-10).

Empirical g.f.: x*(1 + x^3 - 2*x^4 + 3*x^5 - x^8) / (1 - 2*x - 2*x^5 + 2*x^6 - 4*x^7 + x^10). - Colin Barker, Jan 08 2019

EXAMPLE

Some solutions for n=4:

..1..6..3..4..9....1..6..7..4..9...10..2.12..4.14....5..2..7..4..9

.10..0.12..2.14...10..0.12..2..3....6..0..1..9..3...10..0..1.13..3

.11..5.13..7..8...11..5.13.14..8...11..5.13..7..8...11.12..6.14..8

CROSSREFS

Row 2 of A264628.

Sequence in context: A203318 A282776 A283015 * A283059 A283081 A344265

Adjacent sequences:  A264626 A264627 A264628 * A264630 A264631 A264632

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 19 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 24 09:52 EDT 2021. Contains 346273 sequences. (Running on oeis4.)