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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A204223 Number of (n+1)X2 0..2 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards 5

%I

%S 81,450,2500,11100,49284,192474,751689,2707641,9753129,33291180,

%T 113635600,373782240,1229484096,3940246872,12627691129,39725765841,

%U 124974269289,387960161310,1204352604900,3702976839180,11385401099076

%N Number of (n+1)X2 0..2 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards

%C Column 1 of A204230

%H R. H. Hardin, <a href="/A204223/b204223.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 9*a(n-1) -2*a(n-2) -210*a(n-3) +498*a(n-4) +1782*a(n-5) -7500*a(n-6) -4716*a(n-7) +53007*a(n-8) -25623*a(n-9) -209346*a(n-10) +253710*a(n-11) +460144*a(n-12) -940824*a(n-13) -427120*a(n-14) +1906032*a(n-15) -338256*a(n-16) -2148336*a(n-17) +1287648*a(n-18) +1144800*a(n-19) -1233792*a(n-20) -62208*a(n-21) +414720*a(n-22) -124416*a(n-23)

%e Some solutions for n=4

%e ..1..0....2..1....1..2....1..2....1..1....0..2....0..1....0..1....2..0....0..2

%e ..0..1....0..2....2..1....2..2....0..0....2..0....2..0....2..0....0..1....1..2

%e ..1..1....1..2....2..1....1..2....2..0....1..2....2..0....1..2....0..2....0..2

%e ..0..2....2..1....2..2....2..2....0..2....1..2....2..2....2..0....1..2....2..1

%e ..1..2....1..2....2..1....2..1....0..2....1..2....2..0....1..2....2..2....2..2

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 13 2012

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 October 18 13:35 EDT 2021. Contains 348068 sequences. (Running on oeis4.)