cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A331016 Lexicographically earliest sequence of distinct positive terms that can be viewed as an irregular table where the n-th row has max(1, A001221(a(n))) terms and for n > 1, T(n, k) is a multiple of the k-th prime factor of a(n) (=A027748(a(n), k)).

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%I A331016 #13 Jan 09 2020 18:31:23
%S A331016 1,2,3,4,5,6,9,12,8,15,10,18,20,14,25,16,21,22,30,24,7,35,26,27,28,32,
%T A331016 11,34,33,40,36,39,42,45,49,38,13,48,44,56,46,55,50,17,51,66,52,60,54,
%U A331016 57,63,65,58,69,70,72,75,77,62,19,78,64,81,68,88,74,84
%N A331016 Lexicographically earliest sequence of distinct positive terms that can be viewed as an irregular table where the n-th row has max(1, A001221(a(n))) terms and for n > 1, T(n, k) is a multiple of the k-th prime factor of a(n) (=A027748(a(n), k)).
%C A331016 This sequence is a permutation of the natural numbers:
%C A331016 - beyond the sixth row, every even number gives rise to another even number,
%C A331016 - so eventually every even number appears in the sequence,
%C A331016 - for any odd prime number p we will have infinitely many multiples of 2*p,
%C A331016 - giving rise to infinitely many multiples of p,
%C A331016 - and eventually every number will appear.
%H A331016 Rémy Sigrist, <a href="/A331016/b331016.txt">Table of n, a(n) for n = 1..10000</a>
%H A331016 Rémy Sigrist, <a href="/A331016/a331016.gp.txt">PARI program for A331016</a>
%H A331016 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%e A331016 The first terms and rows are:
%e A331016   n   a(n)  row(n)
%e A331016   --  ----  ------------
%e A331016    1     1  [1]
%e A331016    2     2  [2]
%e A331016    3     3  [3]
%e A331016    4     4  [4]
%e A331016    5     5  [5]
%e A331016    6     6  [6, 9]
%e A331016    7     9  [12]
%e A331016    8    12  [8, 15]
%e A331016    9     8  [10]
%e A331016   10    15  [18, 20]
%e A331016   11    10  [14, 25]
%o A331016 (PARI) See Links section.
%Y A331016 See A331010 for similar sequences.
%Y A331016 Cf. A001221, A027748.
%K A331016 nonn,look,tabf
%O A331016 1,2
%A A331016 _Rémy Sigrist_, Jan 06 2020