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%I #5 Apr 19 2016 01:07:34
%S 6,28,4512,65520,694400
%N 0+1+Prime power perfect numbers: if n=Product p_i^r_i then 01PPsigma(n)= Product {Sum p_i^r_i, 0<=s_i<=r_i, s_i is 0 or one or prime} 01PPsigma(n)=2*n.
%C Factorizations : 2*3, 2^2*7, 2^5*3*47, 2^4*3^2*5*7*13, 2^7*5^2*7*31
%C No other terms < 3000000000. - _Jud McCranie_, Jul 16 2004
%e 01PPsigma(2^5*3^3)=(1+2+2^2+2^3+2^5)*(1+3+3^2+3^3)=1880
%e All exponents of the terms are 0 or 1 or prime.
%Y Cf. A096290, A095724.
%K nonn
%O 1,1
%A _Yasutoshi Kohmoto_, Jul 08 2004