login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A278267 Number of n X 2 0..3 arrays with every element plus 1 mod 4 equal to some element at offset (-1,-1) (-1,0) (-1,1) (0,-1) (0,1) (1,-1) or (1,0), with upper left element zero. 1
0, 4, 47, 395, 3453, 30475, 268257, 2360984, 20781746, 182923358, 1610107387, 14172312272, 124745996060, 1098025707095, 9664923050975, 85071539806558, 748807501780793, 6591072360831728, 58015223889383283, 510655325670196475 (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) = 10*a(n-1) - 14*a(n-2) + 37*a(n-3) - 65*a(n-4) + 70*a(n-5) - 76*a(n-6) + 74*a(n-7) - 32*a(n-8).

Empirical g.f.: x^2*(4 + 7*x - 19*x^2 + 13*x^3 - 4*x^4 + 9*x^5 - 8*x^6) / (1 - 10*x + 14*x^2 - 37*x^3 + 65*x^4 - 70*x^5 + 76*x^6 - 74*x^7 + 32*x^8). - Colin Barker, Feb 09 2019

EXAMPLE

Some solutions for n=4:

..0..2. .0..3. .0..2. .0..3. .0..1. .0..2. .0..2. .0..3. .0..0. .0..3

..1..3. .1..2. .1..3. .1..2. .0..2. .1..3. .1..3. .1..2. .1..3. .1..2

..3..0. .3..0. .0..2. .0..2. .3..2. .2..3. .2..2. .1..3. .2..1. .1..1

..2..2. .2..1. .3..3. .3..3. .1..1. .0..1. .0..1. .0..2. .0..3. .0..3

CROSSREFS

Column 2 of A278272.

Sequence in context: A186677 A277654 A247767 * A309329 A326434 A319833

Adjacent sequences:  A278264 A278265 A278266 * A278268 A278269 A278270

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 16 2016

STATUS

approved

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

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 27 11:47 EDT 2022. Contains 354097 sequences. (Running on oeis4.)