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Numbers n from which zero or more applications of A003415 will lead to 5.
4

%I #5 Oct 08 2019 16:26:44

%S 5,6,9,14,33,49,62,94,177,445,817,886,913,961,1146,1155,1633,1719,

%T 1822,2006,2173,2209,2306,2625,2649,2825,3255,3430,3450,3871,4018,

%U 4405,4414,4575,4638,4869,5294,5687,6009,6162,6506,6849,8110,8113,8126,8334,8570,9741,9770,10222,10635,11221,12014,13377,13458,13767,13993,15351

%N Numbers n from which zero or more applications of A003415 will lead to 5.

%C Union of {5} with those terms of k of A099308 for which A327968(k) = 5.

%H Antti Karttunen, <a href="/A328115/b328115.txt">Table of n, a(n) for n = 1..10000</a>

%o (PARI)

%o A003415checked(n) = if(n<=1, 0, my(f=factor(n), s=0); for(i=1, #f~, if(f[i,2]>=f[i,1],return(0), s += f[i, 2]/f[i, 1])); (n*s));

%o isA328115(n) = { while((n>5), n = A003415checked(n)); (5==n); };

%o k=0; n=0; while(k<100, n++; if(isA328115(n), k++; print1(n, ", ")));

%Y Cf. A003415, A099308, A327968, A327975, A328117.

%K nonn

%O 1,1

%A _Antti Karttunen_, Oct 07 2019