|
| |
|
|
A157545
|
|
Half the number of length n integer sequences with sum zero and sum of squares 338.
|
|
1
| |
|
|
1, 9, 90, 1570, 32775, 596253, 10391500, 188323164, 3295910835, 51520770235, 737464758030, 9942564439314, 128439149539155, 1604475021960825, 19461485770566600, 229260099669952384, 2617537416673754961
(list; graph; refs; listen; history; 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,0,338)/2.
|
|
|
CROSSREFS
| Sequence in context: A127769 A062815 A160569 * A157558 A157584 A128384
Adjacent sequences: A157542 A157543 A157544 * A157546 A157547 A157548
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| R. H. Hardin (rhhardin(AT)att.net) Mar 02 2009
|
| |
|
|
