OFFSET
1,1
COMMENTS
Without the a(n) > a(n-1) constraint, the sequence would be A018930.
EXAMPLE
a(2)=4 because 3^2+4^2=5^2, a(3)=12 because 3^2+4^2+12^2=13^2 etc.
MATHEMATICA
a = {3}; For[k = 1 + a[[Length[a]]], Length[a] < 11, While[ ! IntegerQ[Sqrt[(k)^2 + Sum[(a[[t]])^2, {t, 1, Length[a]}]]], k++ ]; AppendTo[a, k]]; a
PROG
(PARI) q=3; s=9; for(n=1, 30, b=0; fordiv(s, d, if(d*d>=s, break); t=(s\d-d)/2; if(t>q, b=t); ); q=b; print1(q, ", "); s+=q^2); \\ Max Alekseyev, Nov 23 2012
CROSSREFS
KEYWORD
nonn
AUTHOR
Artur Jasinski, Jan 23 2007
EXTENSIONS
More terms from Max Alekseyev, Nov 23 2012
STATUS
approved