A291174 - OEIS

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

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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