|
Search: id:A157583
|
|
|
| A157583 |
|
Half the number of length n integer sequences with sum zero and sum of squares 5202. |
|
+0
1
|
|
| 1, 3, 306, 19110, 1405335, 127596189, 10056226796, 714714066732, 47739604854315, 2926869332706055, 164336205885920178, 8620987583406297606, 434508999474316043459, 21294115220098361584440, 1014206441760046027667880
(list; graph; listen)
|
|
|
OFFSET
|
2,2
|
|
|
LINKS
|
Ron 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,0,5202)/2.
|
|
CROSSREFS
|
Sequence in context: A119067 A052505 A071525 this_sequence A085319 A123032 A132305
Adjacent sequences: A157580 A157581 A157582 this_sequence A157584 A157585 A157586
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Ron Hardin (rhhardin(AT)att.net) Mar 02 2009
|
|
|
Search completed in 0.002 seconds
|
