A085253 Numbers having no representation as sum of two powerful numbers (A001694).

1, 3, 4, 6, 7, 11, 14, 15, 19, 21, 22, 23, 27, 30, 38, 39, 42, 46, 47, 49, 51, 55, 56, 60, 62, 66, 67, 69, 70, 71, 75, 77, 78, 79, 83, 84, 86, 87, 92, 93, 94, 95, 102, 103, 105, 107, 110, 111, 114, 115, 118, 119, 120, 123, 131, 138, 139, 142, 143, 147, 151, 154

Offset

1,2

Comments

Complement of A076871.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Powerful Number.

Formula

A085252(a(n)) = 0.

Mathematica

With[{m = 160}, pow = Select[Range[m], # == 1 || Min[FactorInteger[#][[;; , 2]]] > 1 &]; Complement[Range[m], Select[Union[Plus @@@ Tuples[pow, {2}]], # <= m &]]] (* Amiram Eldar, Jan 30 2023 *)

Crossrefs

Cf. A001694, A076871, A085252.

Different from A075434.

Sequence in context: A079249 A306678 A075434 * A207525 A240208 A349555

Adjacent sequences: A085250 A085251 A085252 * A085254 A085255 A085256

Keyword

nonn

Author

Reinhard Zumkeller, Jun 23 2003

Status

approved