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

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A281211 Number of 7 X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards. 1

%I

%S 0,1308,2688,3604,5712,9118,14375,22700,36144,58168,94524,154800,

%T 254959,421560,698756,1159898,1926760,3201376,5318733,8833940,

%U 14666360,24337820,40366132,66914912,110866187,183590176,303864300,502685950,831204864

%N Number of 7 X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

%H R. H. Hardin, <a href="/A281211/b281211.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-3) + 4*a(n-4) - a(n-6) for n>13.

%F Empirical g.f.: x^2*(1308 - 2544*x - 1916*x^2 + 4664*x^3 + 830*x^4 - 2793*x^5 - 12*x^6 + 920*x^7 + 274*x^8 + 40*x^9 - 18*x^10 - 10*x^11) / ((1 - x)^2*(1 - x - x^2)^2). - _Colin Barker_, Feb 18 2019

%e Some solutions for n=4:

%e ..0..1..0..1. .0..0..1..0. .0..0..1..0. .0..1..0..1. .0..1..1..0

%e ..0..0..0..1. .1..0..1..0. .1..0..1..0. .1..0..1..0. .0..0..1..0

%e ..0..1..0..1. .1..1..1..0. .0..1..0..1. .1..0..1..0. .1..0..1..0

%e ..0..1..0..0. .0..0..1..0. .0..1..0..1. .1..0..1..0. .0..1..0..1

%e ..0..1..1..0. .1..0..1..0. .0..0..1..0. .0..1..1..0. .0..1..1..1

%e ..0..0..1..0. .1..0..1..0. .1..0..1..0. .0..0..1..0. .0..1..0..1

%e ..1..0..1..1. .0..1..0..1. .0..1..0..1. .1..0..1..0. .0..1..0..0

%Y Row 7 of A281205.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 17 2017

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 January 23 10:48 EST 2020. Contains 331171 sequences. (Running on oeis4.)