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!)
A157588 Half the number of length n integer sequences with sum zero and sum of squares 6272. 1
1, 9, 54, 18490, 3080025, 281083131, 20455480647, 1378645284663, 90798695826120, 5747081242763245, 353783429708291517, 21210677666294419836, 1217797507802900629878, 66543379957754376544455 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

R. H. Hardin, Table of n, a(n) for n=2..50

FORMULA

[cache enabling] count(n,s,ss)->count(n,t,tt) where t=s mod n, q=(t-s)/n, tt=ss+2*q*s+n*q^2; count(n,t,tt)=sum[i^2<=tt]{ count(n-1,t-i,tt-i^2) }. a(n)=count(n,0,6272)/2.

CROSSREFS

Sequence in context: A205814 A157546 A157560 * A270575 A058849 A058852

Adjacent sequences:  A157585 A157586 A157587 * A157589 A157590 A157591

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 02 2009

STATUS

approved

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 August 10 22:36 EDT 2022. Contains 356046 sequences. (Running on oeis4.)