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!)
A264677 Number of (2+1) X (n+1) arrays of permutations of 0..n*3+2 with each element having directed index change -1,-1 1,0 -1,-2 -2,-2 or 0,1. 1
1, 2, 10, 29, 75, 201, 588, 1700, 4785, 13401, 37905, 107598, 304638, 860789, 2433555, 6885713, 19483112, 55110392, 155875521, 440924465, 1247301569, 3528321578, 9980556450, 28232081677, 79861067099, 225905953689, 639026458132 (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) = 3*a(n-1) - 3*a(n-2) + 5*a(n-3) + 7*a(n-4) - 5*a(n-5) + 7*a(n-6) - 3*a(n-7) + a(n-8) - a(n-9).

Empirical g.f.: x*(1 - x + 7*x^2 + x^4 + 4*x^5 - 2*x^6 - x^8) / (1 - 3*x + 3*x^2 - 5*x^3 - 7*x^4 + 5*x^5 - 7*x^6 + 3*x^7 - x^8 + x^9). - Colin Barker, Jan 08 2019

EXAMPLE

Some solutions for n=4:

.12..7..9..2..3....6..7..1..2..3....6.13..8..2..3...12..0..1..2..3

..0..1..6.14..4....0.12.13.14..4....0..1.14..7..4...11.13..6.14..4

..5.10.11..8.13....5.10.11..8..9....5.10.11.12..9....5.10..7..8..9

CROSSREFS

Row 2 of A264676.

Sequence in context: A076438 A203551 A192976 * A101561 A279263 A295525

Adjacent sequences:  A264674 A264675 A264676 * A264678 A264679 A264680

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 20 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 May 31 02:51 EDT 2020. Contains 334747 sequences. (Running on oeis4.)