The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A194507

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A194507

a(n) = y is the unique solution to y*phi(y) = A082473(n).
(history; published version)

#23 by Susanna Cuyler at Sun Sep 29 20:22:45 EDT 2019

STATUS

proposed

approved

#22 by Michael De Vlieger at Sun Sep 29 17:15:52 EDT 2019

STATUS

editing

proposed

#21 by Michael De Vlieger at Sun Sep 29 17:15:47 EDT 2019

MATHEMATICA

Block[{nn = 3000, s, t}, s = Array[EulerPhi[#] (Sqrt@ # /. (c_: 1) a_^(b_: 0) :> (c a^b)^2) &, nn]; t = TakeWhile[Union@ s, # <= nn &]; Map[Block[{y = 1}, While[y EulerPhi@ y != #, y++]; y] &, t]] (* Michael De Vlieger, Sep 29 2019, after Bill Gosper at A007913 *)

STATUS

proposed

editing

#20 by Antti Karttunen at Sun Sep 29 16:48:31 EDT 2019

STATUS

editing

proposed

#19 by Antti Karttunen at Sat Sep 28 17:40:49 EDT 2019

CROSSREFS

Cf. A002618, A082473, A327173 (inverse permutation).

#18 by Antti Karttunen at Sat Sep 28 17:38:48 EDT 2019

LINKS

Antti Karttunen, <a href="/A194507/b194507.txt">Table of n, a(n) for n = 1..20001</a>

#17 by Antti Karttunen at Sat Sep 28 17:27:14 EDT 2019

COMMENTS

The permutation which sorts rearranges the terms of A002618 into ascending order. - Antti Karttunen, Sep 28 2019

#16 by Antti Karttunen at Sat Sep 28 17:24:51 EDT 2019

COMMENTS

The permutation which sorts the terms of A002618 into ascending order. - Antti Karttunen, Sep 28 2019

#15 by Antti Karttunen at Sat Sep 28 17:20:30 EDT 2019

FORMULA

a(n) = A327172(A082473(n)). - _From _Antti Karttunen_, Sep 28 2019: (Start)

a(n) = A327172(A082473(n)).

A002618(a(n)) = A082473(n).

(End)

#14 by Antti Karttunen at Sat Sep 28 17:09:29 EDT 2019

LINKS

<a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>