

A157541


Half the number of length n integer sequences with sum zero and sum of squares 162.


1



1, 3, 54, 610, 7575, 124005, 1721692, 21584676, 254430555, 2752913955, 27276416970, 252510790038, 2245919946361, 19423497389310, 163254969718200, 1331429118674408, 10524020807274019, 80607360684092143, 599129356328684230
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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=(ts)/n, tt=ss+2*q*s+n*q^2; count(n,t,tt)=sum[i^2<=tt]{ count(n1,ti,tti^2) }. a(n)=count(n,0,162)/2.


CROSSREFS

Sequence in context: A275566 A174782 A119294 * A182159 A065102 A223926
Adjacent sequences: A157538 A157539 A157540 * A157542 A157543 A157544


KEYWORD

nonn


AUTHOR

R. H. Hardin Mar 02 2009


STATUS

approved



