|
Search: id:A157555
|
|
|
| A157555 |
|
Half the number of length n integer sequences with sum zero and sum of squares 1058. |
|
+0
1
|
|
| 1, 3, 150, 5070, 182175, 5887791, 180232444, 5773910724, 178835952285, 4946264437455, 125256800641170, 2987737855296558, 68285219070825029, 1509200139206357640, 32387266774022554680, 675011623200542959496
(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,0,1058)/2.
|
|
CROSSREFS
|
Sequence in context: A037122 A118840 A111816 this_sequence A157578 A137802 A100203
Adjacent sequences: A157552 A157553 A157554 this_sequence A157556 A157557 A157558
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Ron Hardin (rhhardin(AT)att.net) Mar 02 2009
|
|
|
Search completed in 0.002 seconds
|
