cp's OEIS Frontend

A285417 Lexicographically earliest sequence of distinct positive terms such that the product of two consecutive terms is divisible by p^5 for some prime p.

%I A285417 #8 Apr 20 2017 12:34:35
%S A285417 1,32,2,16,4,8,12,24,20,40,28,48,6,64,3,81,9,27,18,54,36,56,44,72,52,
%T A285417 80,10,96,5,128,7,160,11,192,13,224,14,112,22,144,26,176,30,162,15,
%U A285417 243,17,256,19,288,21,320,23,352,25,125,50,208,34,240,38,272,42
%N A285417 Lexicographically earliest sequence of distinct positive terms such that the product of two consecutive terms is divisible by p^5 for some prime p.
%C A285417 This sequence is a permutation of the natural numbers.
%H A285417 Rémy Sigrist, <a href="/A285417/b285417.txt">Table of n, a(n) for n = 1..10000</a>
%H A285417 Rémy Sigrist, <a href="/A285417/a285417.txt">C++ program for A285417</a>
%H A285417 Rémy Sigrist, <a href="/A285417/a285417.png">Scatterplot of the first 150000 terms</a>
%H A285417 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%e A285417 The first terms, alongside the primes p such that p^5 divides a(n)*a(n+1), are:
%e A285417 n       a(n)    p
%e A285417 --      ----    -
%e A285417 1       1       2
%e A285417 2       32      2
%e A285417 3       2       2
%e A285417 4       16      2
%e A285417 5       4       2
%e A285417 6       8       2
%e A285417 7       12      2
%e A285417 8       24      2
%e A285417 9       20      2
%e A285417 10      40      2
%e A285417 11      28      2
%e A285417 12      48      2
%e A285417 13      6       2
%e A285417 14      64      2
%e A285417 15      3       3
%e A285417 16      81      3
%e A285417 17      9       3
%e A285417 18      27      3
%e A285417 19      18      3
%e A285417 20      54      3
%e A285417 ...
%e A285417 1476    7744    2
%e A285417 1477    811     2, 3
%e A285417 1478    7776    2, 3
%e A285417 1479    813     3
%e A285417 ...
%Y A285417 Cf. A285296.
%K A285417 nonn
%O A285417 1,2
%A A285417 _Rémy Sigrist_, Apr 18 2017