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A157583 Half the number of length n integer sequences with sum zero and sum of squares 5202. 1
1, 3, 306, 19110, 1405335, 127596189, 10056226796, 714714066732, 47739604854315, 2926869332706055, 164336205885920178, 8620987583406297606, 434508999474316043459, 21294115220098361584440, 1014206441760046027667880 (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,0,5202)/2.

CROSSREFS

Sequence in context: A052505 A307020 A071525 * A218361 A085319 A123032

Adjacent sequences:  A157580 A157581 A157582 * A157584 A157585 A157586

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 02 2009

STATUS

approved

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Last modified May 22 11:15 EDT 2022. Contains 353949 sequences. (Running on oeis4.)