A291174 Unitary totient superdeficient numbers: numbers n > 1 such that s(n)/n < s(m)/m for all m < n, where s is the sum of iterated uphi (A047994).

2, 3, 6, 12, 14, 26, 30, 42, 186, 210, 2310, 66990, 903210, 1037190, 1138830

Offset

1,1

Comments

The unitary version of A291173.

Links

Table of n, a(n) for n=1..15.

Mathematica

uphi[n_] :=  If[n == 1, 1, (Times @@ (Table[#[[1]]^#[[2]] - 1, {1}] & /@  FactorInteger[n]))[[1]]]; Function[s, Flatten[First@Position[s, #] & /@ Union@Rest@FoldList[Max, 0, s]]]@ Table[n/(Total@FixedPointList[uphi, n] - (n-5)), {n, 2, 10^4}]+1 (* after Michael De Vlieger at A286268 and Alonso del Arte at A092693 *)

Crossrefs

Cf. A047994, A291173.

Sequence in context: A020492 A110590 A329401 * A281110 A252792 A284638

Adjacent sequences: A291171 A291172 A291173 * A291175 A291176 A291177

Keyword

nonn,more

Author

Amiram Eldar, Aug 19 2017

Status

approved