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!)
A254915 Number of (n+2)X(1+2) 0..1 arrays with every 3X3 subblock sum of the two maximums of the central row and central column plus the two minimums of the diagonal and antidiagonal nondecreasing horizontally and vertically 2
512, 2812, 14184, 65548, 294960, 1302500, 5646340, 24197932, 102910460, 435448220, 1835734148, 7717606664, 32383016692, 135697390944, 568079847724, 2376537629288, 9937162336296, 41536068400632, 173571311968704 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 1 of A254922

LINKS

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

FORMULA

Empirical: a(n) = 7*a(n-1) -13*a(n-2) +11*a(n-3) -13*a(n-4) -60*a(n-5) -32*a(n-6) +210*a(n-7) +501*a(n-8) -221*a(n-9) +109*a(n-10) -981*a(n-11) -1875*a(n-12) +1430*a(n-13) +856*a(n-14) -180*a(n-15) +468*a(n-16) -216*a(n-17)

EXAMPLE

Some solutions for n=4

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

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

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

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

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

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

CROSSREFS

Sequence in context: A258530 A254922 A254253 * A257154 A254743 A254736

Adjacent sequences:  A254912 A254913 A254914 * A254916 A254917 A254918

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 10 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 December 2 20:25 EST 2021. Contains 349445 sequences. (Running on oeis4.)