A375012 A cycle of length 5 when iterating x <- phi(sigma(x)).
339026688000000, 377975808000000, 424639621324800, 483184764518400, 453984583680000
Offset: 1
Examples
phi(sigma(339026688000000)) = 377975808000000, ... phi(sigma(453984583680000)) = 339026688000000, so 339026688000000 is in the sequence.
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