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!)
A297310 Number of n X 4 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 or 2 neighboring 1s. 1

%I

%S 7,66,497,3808,29212,223995,1717882,13174266,101033369,774822892,

%T 5942100272,45569854023,349474289622,2680111429330,20553721242845,

%U 157626080234992,1208831279237072,9270503076704855,71095304015354510

%N Number of n X 4 0..1 arrays with every 1 horizontally or antidiagonally adjacent to 1 or 2 neighboring 1s.

%H R. H. Hardin, <a href="/A297310/b297310.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) + 26*a(n-2) + 22*a(n-3) - 43*a(n-4) - a(n-5) + 7*a(n-6) - a(n-7) - a(n-8) for n>9.

%F Empirical g.f.: x*(7 + 38*x + 51*x^2 - 50*x^3 - 93*x^4 + 50*x^5 + 2*x^6 - 10*x^7 + x^8) / ((1 - 7*x - 5*x^2 - x^3)*(1 + 3*x - 6*x^3 + 4*x^4 - x^5)). - _Colin Barker_, Feb 26 2019

%e Some solutions for n=5:

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

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

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

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

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

%Y Column 4 of A297314.

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 28 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 25 14:40 EST 2022. Contains 350572 sequences. (Running on oeis4.)