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Composite numbers of form 8n+5 with all prime factors of form 8m+5.
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%I #2 Mar 30 2012 17:26:34

%S 125,325,725,845,925,1325,1525,1885,2197,2405,2525,2725,3125,3445,

%T 3725,3925,3965,4205,4325,4525,4901,4925,5365,5725,6253,6565,6725,

%U 6845,6925,7085,7325,7685,7925,8125,8725,8845,8957,9325,9685,9725,9805,9925,10205

%N Composite numbers of form 8n+5 with all prime factors of form 8m+5.

%C There are no squares and no semiprimes in the sequence.

%e 125=5^3, 325=5^2*13, 725=5^2*29.

%t Do[nn=8n+5;If[ !PrimeQ[nn]&&{5}==Union[Mod[(fi=First/@FactorInteger[nn]),8]],Print[nn]],{n,2*10^3}]

%Y Cf. A004770 Numbers of form 8n+5, A175461 Semiprimes of form 8n+5, A007521 Primes of form 8n+5.

%K nonn

%O 1,1

%A _Zak Seidov_, May 27 2010