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!)
A252133 Number of (n+2) X (2+2) 0..3 arrays with every 3 X 3 subblock row, column, diagonal and antidiagonal sum not equal to 0 3 4 6 or 7. 2
134, 156, 431, 1183, 3163, 8684, 24031, 66098, 181896, 501355, 1381325, 3804929, 10482568, 28879979, 79562524, 219191134, 603866443, 1663632329, 4583248173, 12626699534, 34786145503, 95834674276, 264021357876, 727370136485 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A252139.

LINKS

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

FORMULA

Empirical: a(n) = 2*a(n-1) + a(n-2) + 4*a(n-3) - a(n-4) - 4*a(n-5) - 3*a(n-6) + a(n-8) + a(n-9) for n>11.

Empirical g.f.: x*(134 - 112*x - 15*x^2 - 371*x^3 - 124*x^4 + 143*x^5 + 225*x^6 + 75*x^7 - 13*x^8 - 64*x^9 - 4*x^10) / ((1 - x)*(1 - x - 2*x^2 - 6*x^3 - 5*x^4 - x^5 + 2*x^6 + 2*x^7 + x^8)). - Colin Barker, Mar 20 2018

EXAMPLE

Some solutions for n=4:

..3..3..3..3....3..3..2..3....3..3..3..2....3..3..3..2....3..3..3..3

..3..3..3..3....3..3..3..3....3..3..3..3....3..3..3..3....3..2..3..3

..3..3..3..2....3..3..3..3....2..3..3..3....3..3..2..3....3..3..3..2

..3..3..3..3....3..2..3..3....3..3..3..3....2..3..3..3....3..3..3..3

..2..3..3..3....3..3..3..2....3..3..3..2....3..3..3..3....3..3..3..3

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

CROSSREFS

Cf. A252139.

Sequence in context: A208626 A061491 A274132 * A255795 A048128 A047824

Adjacent sequences:  A252130 A252131 A252132 * A252134 A252135 A252136

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 14 2014

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 9 01:20 EST 2021. Contains 349614 sequences. (Running on oeis4.)