OFFSET
1,2
COMMENTS
From Franklin T. Adams-Watters, Aug 29 2009: (Start)
The k_i must all be positive integers.
Note that every integer > 33 is the sum of 5 positive squares, and for n > 5, every integer > n+13 is the sum of n positive squares. (End)
EXAMPLE
34 = 2*(4^2 + 1^2), 42 = 3*(3^2 + 2^2 + 1^2), thus 34 and 42 are in the sequence.
PROG
(PARI) issumsqs(n, k) = if(n<=0||k<=0, return(k==0&&n==0)); forstep(j=sqrtint(n), max(sqrtint(n\k), 1), -1, if(issumsqs(n-j^2, k-1), return(1))); 0
isa(n)=local(ds); ds=divisors(n); for(k=1, (#ds+1)\2, if(issumsqs(n\ds[k], ds[k]), return(1))); 0
for(n=1, 200, if(isa(n), print1(n", "))) \\ Franklin T. Adams-Watters, Aug 29 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonas Wallgren, Aug 10 2009, Aug 17 2009
EXTENSIONS
More terms from Franklin T. Adams-Watters, Aug 29 2009
STATUS
approved