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a(n) is a refactorable number and the sum of all refactorable numbers <= a(n) is also a refactorable number.
2

%I #7 Jan 11 2014 12:40:39

%S 1,448,1384,1520,2216,2240,2264,2316,2432,2488,2536,2560,3280,3324,

%T 3384,3420,3464,3600,3712,3736,3924,12392,12560,12576,12664,12720,

%U 12756,12780,12828,12992,13044,13116,17360,17432,18072,18108,18336,18368,18636,18664

%N a(n) is a refactorable number and the sum of all refactorable numbers <= a(n) is also a refactorable number.

%H Giovanni Resta, <a href="/A235177/b235177.txt">Table of n, a(n) for n = 1..1000</a>

%e The sum of the terms of A033950 <= 448 equals 9120, which is A033950(616).

%Y Cf. A033950, A235176.

%K nonn

%O 1,2

%A _Ivan N. Ianakiev_, Jan 04 2014

%E a(8)-a(40) from _Giovanni Resta_, Jan 04 2014