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A157591 Half the number of length n integer sequences with sum zero and sum of squares 6962. 1
1, 3, 354, 35410, 3079815, 254391501, 20017977868, 1645049437956, 130713839323245, 9274041450918255, 602446992143570574, 36862449524697504786, 2161188475320550751257, 122528449769743353508305 (list; graph; refs; listen; history; text; 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,0,6962)/2.

CROSSREFS

Sequence in context: A039515 A209426 A037302 * A005336 A062226 A266454

Adjacent sequences:  A157588 A157589 A157590 * A157592 A157593 A157594

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 02 2009

STATUS

approved

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Last modified September 15 14:32 EDT 2019. Contains 327078 sequences. (Running on oeis4.)