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A157585 Half the number of length n integer sequences with sum zero and sum of squares 5618. 1
1, 3, 330, 27570, 2233965, 165759111, 11709395180, 864416336904, 61700500723635, 3932420281395045, 229474040212588578, 12613127103936869874, 664285970637825836755, 33831654295810674426165, 1673010760008675643666440 (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,0,5618)/2.

CROSSREFS

Sequence in context: A235334 A160070 A112895 * A045645 A245190 A005335

Adjacent sequences:  A157582 A157583 A157584 * A157586 A157587 A157588

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 02 2009

STATUS

approved

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Last modified June 25 20:02 EDT 2022. Contains 354851 sequences. (Running on oeis4.)