[seqfan] Re: Symmetric Relations and Self-Inverse Permutations
franktaw at netscape.net
franktaw at netscape.net
Thu Apr 16 23:46:42 CEST 2009
I just submitted:
%I A159587
%S A159587
1,3,2,5,4,35,8,7,11,21,9,55,16,15,14,13,19,65,17,33,10,39,25,77,23,45,
%T A159587
29,51,27,1001,32,31,20,57,6,85,41,63,22,69,37,715,47,75,26,87,43,91,53,
%U A159587
93,28,95,49,115,12,99,34,111,61,1309,59,117,38,67,18,455,64,123,40,429
%N A159587 a(n) is the smallest number not yet in the sequence with the
same
number of distinct prime divisors as n, but relatively prime to n.
%C A159587 This is a self-inverse permutation of the positive integers.
....
I'm wondering about the record highs for this sequence. It appears
that these occur at values in A060735 (numbers p# * k where p# is the
primorial function of a prime p, and k < q where q is the next prime >
p). Certainly all numbers in A060735 are indices of record highs in
A159587; it seems certain that they are the only ones, but I don't
quite see how to prove it.
I did check that these are all the record highs up to 1200.
Franklin T. Adams-Watters
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