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%I #7 Mar 15 2024 08:04:09
%S 6,28,36720,222768,12646368,5154170112,34725010231296
%N 4-infinitary perfect numbers: n such that 4-infinitary-sigma(n)=2*n.
%C Here 4-infinitary-sigma(a) means sum of 4-infinitary-divisor of a. If n=Product p(i)^r(i) and d=Product p(i)^s(i), each s(i) has a digit a<=b in its 4-ary expansion everywhere that the corresponding r(i) has a digit b, then d is a 4-infinitary-divisor of n.
%F {n: A074847(n) = 2*n}. - _R. J. Mathar_, Mar 13 2024
%e Factorizations: 2*3, 2^2*7, 2^4*3^3*5*17, 2^4*3^2*7*13*17, 2^5*3^4*7*17*41, 2^8*3^2*7*13^2*31*61, 2^12*3^5*7*11*41*43*257.
%Y Cf. A074847.
%K nonn
%O 1,1
%A _Yasutoshi Kohmoto_, Sep 10 2002
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