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!)
A190073 Number of arrangements of 4 nonzero numbers x(i) in -n..n with the sum of div(x(i),x(i+1)), where div(a,b)=a/b produces the integer quotient implying a nonnegative remainder, equal to zero 1

%I #5 Mar 31 2012 12:36:19

%S 0,40,166,483,1126,2276,4150,6946,10909,16353,23728,33290,45591,61100,

%T 80161,103121,130833,163649,202441,247746,300269,360694,430361,508989,

%U 598090,698534,811133,936287,1075989,1230312,1401309,1589246,1795222

%N Number of arrangements of 4 nonzero numbers x(i) in -n..n with the sum of div(x(i),x(i+1)), where div(a,b)=a/b produces the integer quotient implying a nonnegative remainder, equal to zero

%C Row 3 of A190071

%H R. H. Hardin, <a href="/A190073/b190073.txt">Table of n, a(n) for n = 1..200</a>

%e Some solutions for n=4

%e ..4...-3...-3...-4....2...-4...-1...-1...-1...-4...-4....3....2....3...-2....1

%e .-4....3....3....1....3....3...-1....4....3...-3...-4....3...-1...-1...-4....4

%e ..3....3....3....4...-2...-4...-3...-4....2....2...-4....2...-1...-4...-4...-3

%e ..1...-4....4....1...-3...-3....2...-2....3....3....3...-1...-1...-3....3...-3

%K nonn

%O 1,2

%A _R. H. Hardin_ May 04 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 16 08:27 EDT 2024. Contains 371698 sequences. (Running on oeis4.)