OFFSET
1,1
COMMENTS
Complement of A085253. - Reinhard Zumkeller, Jun 23 2003
REFERENCES
Aleksandar Ivić, The Riemann Zeta-Function, Wiley, NY, 1985, see p. 439.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Valentin Blomer, Binary quadratic forms with large discriminants and sums of two squareful numbers II, Journal of the London Mathematical Society 71:1 (2005), pp. 69-84.
Alexander Kalmynin and Segei Konyagin, Large gaps between sums of two squareful numbers, arXiv:2303.14833 [math.NT], 2023.
Eric Weisstein's World of Mathematics, Powerful Number.
FORMULA
A085252(a(n)) > 0. - Reinhard Zumkeller, Jun 23 2003
Blomer shows that there are x/log^k x sums of two powerful numbers up to x, where k = 0.20629947... is A261883. - Charles R Greathouse IV, Sep 04 2015
MATHEMATICA
With[{m = 120}, pow = Select[Range[m], # == 1 || Min[FactorInteger[#][[;; , 2]]] > 1 &]; Select[Union[Plus @@@ Tuples[pow, {2}]], # <= m &]] (* Amiram Eldar, Jan 30 2023 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Nov 25 2002
EXTENSIONS
More terms from Vladeta Jovovic, Nov 25 2002
STATUS
approved