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A157543 Half the number of length n integer sequences with sum zero and sum of squares 242. 1
1, 3, 66, 1330, 19815, 310023, 4512844, 69146820, 1023450345, 13538157655, 163977086526, 1870633964706, 20447484311345, 216134818489905, 2218284360150120, 22111545640638832, 213615563307370209 (list; graph; refs; listen; history; text; internal format)
OFFSET
2,2
LINKS
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,0,242)/2.
CROSSREFS
Sequence in context: A256151 A238471 A259457 * A368596 A157984 A187547
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 02 2009
STATUS
approved

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Last modified July 13 22:24 EDT 2024. Contains 374288 sequences. (Running on oeis4.)