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A335327 Numbers k such that iphi(k) divides k, where iphi is an infinitary analog of Euler's phi function (A091732). 0
1, 2, 6, 12, 24, 72, 120, 240, 480, 1440, 2880, 5760, 8640, 17280, 65280, 86400, 120960, 130560, 259200, 391680, 783360, 1566720, 2350080, 4700160, 23500800, 32901120, 47001600, 70502400, 94003200, 470016000, 1410048000, 2820096000, 4294901760, 5640192000, 8460288000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..35.

EXAMPLE

6 is a term since iphi(6) = 2 is a divisor of 6.

MATHEMATICA

f[p_, e_] := p^(2^(-1 + Position[Reverse @ IntegerDigits[e, 2], 1])); a[1] = 1; iphi[n_] := Times @@ (Flatten@(f @@@ FactorInteger[n]) - 1);  Select[Range[10^5], Divisible[#, a[#]] &]

CROSSREFS

Cf. A007694, A091732, A319481.

Sequence in context: A170935 A277173 A163264 * A163895 A309016 A302652

Adjacent sequences:  A335324 A335325 A335326 * A335328 A335329 A335330

KEYWORD

nonn

AUTHOR

Amiram Eldar, Jun 01 2020

STATUS

approved

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Last modified June 17 17:43 EDT 2021. Contains 345085 sequences. (Running on oeis4.)