OFFSET
1,2
COMMENTS
n <= a(n); for n > 1, a(n)=n iff n is prime.
MATHEMATICA
Table[Floor@ Sqrt@ Total@ Map[#^2 &, If[IntegerQ@ #, {#, #}, {Last@ #1, First@ #2} & @@ TakeDrop[#, LengthWhile[#, # <= Sqrt@ n &]] &@ Divisors@ n] &@ Sqrt@ n], {n, 79}] (* Michael De Vlieger, Dec 22 2017 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Reinhard Zumkeller, Feb 11 2003
STATUS
approved