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A157601 Half the number of length n integer sequences with sum zero and sum of squares 9522. 1
1, 3, 450, 35490, 3461325, 429808743, 45598808332, 4382814679428, 396120762708465, 32858020705796385, 2495992345644237990, 177151945927883401410, 12079996873394323662971, 800952129262668313107765 (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,0,9522)/2.

CROSSREFS

Sequence in context: A092052 A139999 A140870 * A094454 A261004 A157587

Adjacent sequences:  A157598 A157599 A157600 * A157602 A157603 A157604

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 02 2009

STATUS

approved

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Last modified January 18 17:18 EST 2022. Contains 350455 sequences. (Running on oeis4.)