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A157559 Half the number of length n integer sequences with sum zero and sum of squares 1458. 1
1, 3, 162, 5470, 204405, 10044237, 418371436, 15735232164, 556455670755, 18061671242945, 536877862194894, 14910514196745102, 397858116730316515, 10322446421549098305, 260281325962170069480, 6368185576937692717552 (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,0,1458)/2.

CROSSREFS

Sequence in context: A302950 A173128 A157440 * A157586 A341224 A042439

Adjacent sequences:  A157556 A157557 A157558 * A157560 A157561 A157562

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 02 2009

STATUS

approved

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Last modified August 9 08:38 EDT 2022. Contains 356019 sequences. (Running on oeis4.)