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A085253 Numbers having no representation as sum of two powerful numbers (A001694). 9

%I #10 Jan 30 2023 02:34:52

%S 1,3,4,6,7,11,14,15,19,21,22,23,27,30,38,39,42,46,47,49,51,55,56,60,

%T 62,66,67,69,70,71,75,77,78,79,83,84,86,87,92,93,94,95,102,103,105,

%U 107,110,111,114,115,118,119,120,123,131,138,139,142,143,147,151,154

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

%C Complement of A076871.

%H Amiram Eldar, <a href="/A085253/b085253.txt">Table of n, a(n) for n = 1..10000</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PowerfulNumber.html">Powerful Number</a>.

%F A085252(a(n)) = 0.

%t 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 *)

%Y Cf. A001694, A076871, A085252.

%Y Different from A075434.

%K nonn

%O 1,2

%A _Reinhard Zumkeller_, Jun 23 2003

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Last modified April 23 08:29 EDT 2024. Contains 371905 sequences. (Running on oeis4.)