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!)
A250588 Number of (n+1)X(4+1) 0..2 arrays with nondecreasing max(x(i,j),x(i,j-1)) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction. 2

%I

%S 2375,14983,79415,379397,1686514,7120483,29029369,115191907,448833569,

%T 1723204432,6551633555,24709506002,92716016604,346413672235,

%U 1291010570063,4801025640575,17833372282529,66175132547455

%N Number of (n+1)X(4+1) 0..2 arrays with nondecreasing max(x(i,j),x(i,j-1)) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.

%C Column 4 of A250592.

%C Appears to satisfy the same recurrence relation as A250636.

%H R. H. Hardin, <a href="/A250588/b250588.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 17*a(n-1) -101*a(n-2) +110*a(n-3) +1466*a(n-4) -6607*a(n-5) +2715*a(n-6) +50990*a(n-7) -125338*a(n-8) -69069*a(n-9) +724777*a(n-10) -770521*a(n-11) -1528585*a(n-12) +4147071*a(n-13) -616996*a(n-14) -8587972*a(n-15) +9209705*a(n-16) +6258473*a(n-17) -18241543*a(n-18) +5925196*a(n-19) +15364973*a(n-20) -15498239*a(n-21) -2690737*a(n-22) +12025570*a(n-23) -4880027*a(n-24) -3407185*a(n-25) +3581843*a(n-26) -420145*a(n-27) -810850*a(n-28) +400975*a(n-29) -4790*a(n-30) -48700*a(n-31) +15025*a(n-32) -1500*a(n-33) for n > 35.

%e Some solutions for n=3:

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

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

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

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

%Y Column 4 of A250592.

%Y See also A250636.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 25 2014

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 26 02:14 EDT 2021. Contains 348256 sequences. (Running on oeis4.)