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A131704
a(1)=1, a(n+1) = Sum_{k=1..floor(sqrt(n))} a(floor(k*sqrt(n))).
0
1, 1, 1, 1, 2, 2, 2, 3, 3, 6, 6, 6, 9, 9, 9, 9, 19, 19, 19, 32, 32, 32, 32, 32, 32, 81, 81, 81, 130, 130, 130, 130, 130, 140, 189, 189, 378, 378, 378, 567, 567, 567, 567, 619, 619, 821, 821, 831, 831, 1711, 1711, 1711, 2591, 2640, 2692, 2881, 2881, 2881, 3761, 3963
OFFSET
1,5
MATHEMATICA
a = {1}; Do[AppendTo[a, Sum[a[[Floor[k*Sqrt[n - 1]]]], {k, 1, Floor[Sqrt[n - 1]]}]], {n, 2, 100}]; a (* Stefan Steinerberger, Sep 18 2007 *)
CROSSREFS
Sequence in context: A267160 A374436 A082861 * A327746 A348626 A124492
KEYWORD
nonn
AUTHOR
Leroy Quet, Sep 16 2007
EXTENSIONS
More terms from Stefan Steinerberger, Sep 18 2007
STATUS
approved