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!)
A281055 Number of nX7 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly two elements, and with new values introduced in order 0 sequentially upwards. 1
13, 535, 2828, 10570, 32370, 87995, 221212, 526340, 1201939, 2661939, 5752796, 12190173, 25413086, 52258597, 106216045, 213723050, 426288170, 843735147, 1658596579, 3240610144, 6297012052, 12175728717, 23437264280, 44930659786 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A281056.

LINKS

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

FORMULA

Empirical: a(n) = 5*a(n-1) -6*a(n-2) -4*a(n-3) +5*a(n-4) +9*a(n-5) -3*a(n-6) -3*a(n-7) -3*a(n-8) -9*a(n-9) +6*a(n-11) +8*a(n-12) +2*a(n-13) +3*a(n-14) -3*a(n-15) -3*a(n-16) -3*a(n-17) -a(n-18) -a(n-19) for n>23

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Cf. A281056.

Sequence in context: A300525 A295942 A297518 * A030256 A023332 A309204

Adjacent sequences:  A281052 A281053 A281054 * A281056 A281057 A281058

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jan 13 2017

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 September 25 18:27 EDT 2022. Contains 356986 sequences. (Running on oeis4.)