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%I #27 Jan 12 2020 14:36:07
%S 4,6,8,9,1,0,2,5,7,3,10,12,14,15,16,18,20,21,22,24,25,26,27,28,30,32,
%T 33,34,35,36,38,39,40,42,44,45,46,48,49,50,51,52,54,55,56,57,58,60,62,
%U 63,64,65,66,68,69,70,72,74,75,76,77,78,80,81,82,84,85,86
%N Single-digit numbers in order of appearance in decimal expansions of composite numbers, followed by two-digit numbers in order of appearance, then three-digit numbers and so forth.
%H Rémy Sigrist, <a href="/A330384/b330384.txt">Table of n, a(n) for n = 1..11000</a>
%H Rémy Sigrist, <a href="/A330384/a330384.png">Colored scatterplot of the first 110000 terms</a> (red pixels indicate terms that are prime)
%H Rémy Sigrist, <a href="/A330384/a330384.gp.txt">PARI program for A330384</a>
%e From _Rémy Sigrist_, Dec 24 2019: (Begin)
%e The first terms, alongside the corresponding composite numbers, are:
%e n a(n) Composite
%e -- ---- ---------
%e 1 4 4
%e 2 6 6
%e 3 8 8
%e 4 9 9
%e 5 1 10
%e 6 0 10
%e 7 2 12
%e 8 5 15
%e 9 7 27
%e 10 3 30
%e 11 10 10
%e 12 12 12
%e 13 14 14
%e ...
%e 79 99 99
%e 80 11 110
%e 81 17 117
%e 82 19 119
%e 83 23 123
%e (End)
%o (PARI) See Links section.
%Y Cf. A002808, A321043, A321128.
%K nonn,base,look
%O 1,1
%A _David Williams_, Dec 12 2019
%E More terms from _Rémy Sigrist_, Dec 24 2019
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