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A331018 Lexicographically earliest sequence of distinct positive terms that can be viewed as an irregular table where the n-th row has a(n) terms and for n > 1, T(n, k) is a multiple of k.

%I A331018 #10 Jan 09 2020 19:21:53
%S A331018 1,2,4,3,6,9,8,5,10,12,7,14,15,16,20,18,11,22,21,24,25,30,28,32,27,13,
%T A331018 26,33,36,35,42,49,40,17,34,39,44,45,19,38,48,52,50,54,56,64,63,60,23,
%U A331018 46,51,68,55,66,70,72,81,80,77,84,29,58,57,76,65,78,91
%N A331018 Lexicographically earliest sequence of distinct positive terms that can be viewed as an irregular table where the n-th row has a(n) terms and for n > 1, T(n, k) is a multiple of k.
%C A331018 This sequence is a permutation of the natural numbers as each row starts with the least value not yet in the sequence.
%H A331018 Rémy Sigrist, <a href="/A331018/b331018.txt">Table of n, a(n) for n = 1..10000</a>
%H A331018 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%H A331018 Rémy Sigrist, <a href="/A331018/a331018.gp.txt">PARI program for A331018</a>
%e A331018 The first terms and rows are:
%e A331018   n   a(n)  row(n)
%e A331018   --  ----  -------------------------------------
%e A331018    1     1  [1]
%e A331018    2     2  [2, 4]
%e A331018    3     4  [3, 6, 9, 8]
%e A331018    4     3  [5, 10, 12]
%e A331018    5     6  [7, 14, 15, 16, 20, 18]
%e A331018    6     9  [11, 22, 21, 24, 25, 30, 28, 32, 27]
%e A331018    7     8  [13, 26, 33, 36, 35, 42, 49, 40]
%e A331018    8     5  [17, 34, 39, 44, 45]
%e A331018    9    10  [19, 38, 48, 52, 50, 54, 56, 64, 63, 60]
%e A331018   10    12  [23, 46, 51, 68, 55, 66, 70, 72, 81, 80, 77, 84]
%e A331018   11     7  [29, 58, 57, 76, 65, 78, 91]
%o A331018 (PARI) See Links section.
%Y A331018 See A331010 for similar sequences.
%K A331018 nonn,look,tabf
%O A331018 1,2
%A A331018 _Rémy Sigrist_, Jan 07 2020