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A157589 Half the number of length n integer sequences with sum zero and sum of squares 6498. 1
1, 9, 342, 26670, 1960515, 199230213, 17543249724, 1392949344564, 103992753869385, 7125947800456375, 447172658110001142, 26218227869348323614, 1476897053364550626991, 80893894777513364496600 (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,0,6498)/2.

CROSSREFS

Sequence in context: A354689 A098652 A110695 * A055601 A225328 A203745

Adjacent sequences:  A157586 A157587 A157588 * A157590 A157591 A157592

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 02 2009

STATUS

approved

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Last modified August 18 22:58 EDT 2022. Contains 356215 sequences. (Running on oeis4.)