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A157549 Half the number of length n integer sequences with sum zero and sum of squares 578. 1
1, 3, 102, 2730, 73965, 1747893, 39747932, 941571576, 21552984495, 440593787755, 8246912787894, 145396398912414, 2456171567279885, 40123597587869565, 636426718791995640, 9804070912688974376, 146378210616014587821 (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,0,578)/2.
CROSSREFS
Sequence in context: A037062 A290027 A224817 * A157566 A364418 A157600
KEYWORD
nonn
AUTHOR
R. H. Hardin Mar 02 2009
STATUS
approved

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Last modified May 26 23:01 EDT 2024. Contains 372847 sequences. (Running on oeis4.)