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%I #14 Aug 20 2015 22:39:15
%S 30,756,245520,66056256,1125625012162560,73785850390636462080,
%T 18889393873815823712256,5316911978187903333320785637991776256
%N Numbers k such that sqrt(k + sqrt(k + sqrt(k + ...))) is an even perfect number.
%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/PerfectNumber.html"> PerfectNumber</a>
%F a(n) = 2^(A000043(n) - 2)*(2^A000043(n) - 2)*(2^A000043(n) - 1)*(2^A000043(n) + 1).
%e For n = 1, a(1) = 30 since sqrt(30 + sqrt(30 + sqrt(30 + ...))) = 6, which is an even perfect number.
%Y Cf. A000396, A000043.
%K nonn
%O 1,1
%A _Ilya Gutkovskiy_, Aug 07 2015
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