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%I #10 Apr 21 2013 13:12:12
%S 4,8,9,16,25,27,32,49,64,81,119,121,125,128,161,169,243,256,289,343,
%T 351,361,512,529,595,625,721,729,841,845,959,961,1024,1045,1081,1241,
%U 1323,1331,1369,1375,1547,1681,1792,1849,1855,2048,2187,2197,2209,2401
%N Composite numbers such that the square mean of their prime factors is a prime (where the prime factors are taken with multiplicity and the square mean of c and d is sqrt((c^2+d^2)/2)).
%C All perfect prime powers (A025475) with power > 0 are included.
%C Originally, the definition started with "Nonprime numbers ..." and the first term was equal to 1. This is misleading, since 1 has no prime factors. - _Hieronymus Fischer_, Apr 20 2013
%H Hieronymus Fischer, <a href="/A134601/b134601.txt">Table of n, a(n) for n = 1..10000</a>
%e a(5) = 25, since 25=5*5 and sqrt((5^2+5^2)/2)=5;
%e a(13) = 119, since 119=7*17 and sqrt((7^2+17^2)/2)=sqrt(169)=13.
%Y Cf. A001597, A025475, A134333, A134344, A134376.
%Y Cf. A134600, A134605, A134608, A134611, A134617, A134619, A134621.
%K nonn
%O 1,1
%A _Hieronymus Fischer_, Nov 11 2007
%E Definition clarified and edited by _Hieronymus Fischer_, Apr 20 2013
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