login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A306138 Number of nX3 0..1 arrays with every element unequal to 1, 2, 3, 4, 6 or 7 king-move adjacent elements, with upper left element zero. 1
1, 23, 90, 521, 2787, 14804, 79839, 428041, 2296512, 12329851, 66162665, 355098680, 1905814101, 10228215869, 54894290098, 294613084651, 1581163788591, 8485982858500, 45543581015859, 244428741410877, 1311829444865816 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 3 of A306143.

LINKS

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

FORMULA

Empirical: a(n) = 3*a(n-1) +11*a(n-2) +16*a(n-3) -34*a(n-4) -20*a(n-5) +28*a(n-6) -49*a(n-8) -17*a(n-9) +37*a(n-10) -2*a(n-11) -36*a(n-12) -56*a(n-13) -16*a(n-14) +16*a(n-15) for n>16

EXAMPLE

Some solutions for n=5

..0..0..1. .0..1..1. .0..0..0. .0..1..0. .0..1..1. .0..1..0. .0..1..1

..0..1..0. .1..1..0. .1..0..1. .1..0..1. .1..1..0. .0..1..1. .0..0..1

..0..0..0. .1..0..0. .1..0..1. .1..0..0. .1..0..0. .0..0..0. .1..0..0

..1..1..0. .0..1..0. .1..1..0. .0..0..1. .0..1..0. .0..1..1. .1..0..0

..0..0..0. .0..0..0. .0..0..1. .1..0..1. .0..0..1. .0..1..0. .0..0..1

CROSSREFS

Cf. A306143.

Sequence in context: A142062 A050529 A215613 * A317371 A244632 A042030

Adjacent sequences:  A306135 A306136 A306137 * A306139 A306140 A306141

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 22 2018

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 August 19 18:51 EDT 2019. Contains 326133 sequences. (Running on oeis4.)