A157587 Half the number of length n integer sequences with sum zero and sum of squares 6050.

1, 3, 462, 41230, 2595765, 186323823, 13994329244, 1089068168952, 80599569668955, 5296880405561547, 320164718544367950, 18262041337319290446, 998477188502752352485, 52770671879708445120045, 2707901917377956941817496

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,0,6050)/2.

Crossrefs

Sequence in context: A157601 A094454 A261004 * A054702 A140015 A342067

Adjacent sequences: A157584 A157585 A157586 * A157588 A157589 A157590

Keyword

nonn

Author

R. H. Hardin Mar 02 2009

Status

approved