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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A207520 Number of 4Xn 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 1 0 and 1 0 1 vertically 1
10, 100, 358, 1307, 5458, 19909, 68807, 243954, 851870, 2913994, 9973355, 34091714, 115887871, 393267367, 1334118596, 4519810862, 15299142694, 51772884227, 175141804206, 592296849671, 2002747670245, 6771221110994, 22890878459054 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row 4 of A207519

LINKS

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

FORMULA

Empirical: a(n) = 6*a(n-1) -12*a(n-2) +39*a(n-3) -140*a(n-4) +171*a(n-5) -344*a(n-6) +1128*a(n-7) -630*a(n-8) +1074*a(n-9) -5032*a(n-10) -196*a(n-11) -1552*a(n-12) +16522*a(n-13) +7292*a(n-14) +1958*a(n-15) -40098*a(n-16) -26944*a(n-17) -3424*a(n-18) +68042*a(n-19) +53864*a(n-20) +7280*a(n-21) -81638*a(n-22) -65348*a(n-23) -9198*a(n-24) +67390*a(n-25) +50740*a(n-26) +5022*a(n-27) -37983*a(n-28) -23800*a(n-29) -594*a(n-30) +14633*a(n-31) +6308*a(n-32) -1205*a(n-33) -3792*a(n-34) -684*a(n-35) +688*a(n-36) +730*a(n-37) -34*a(n-38) -170*a(n-39) -100*a(n-40) +8*a(n-41) +16*a(n-42) +8*a(n-43)

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A207394 A207941 A207468 * A207919 A208699 A207255

Adjacent sequences:  A207517 A207518 A207519 * A207521 A207522 A207523

KEYWORD

nonn

AUTHOR

R. H. Hardin Feb 18 2012

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 December 5 03:59 EST 2021. Contains 349530 sequences. (Running on oeis4.)