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%I #60 Jun 16 2021 15:31:57
%S 0,1,2,3,4,5,6,7,8,9,10,12,11,13,14,15,16,19,18,17,20,21,22,23,26,24,
%T 27,25,29,28,30,31,33,32,39,34,37,35,36,38,40,41,43,42,45,44,47,50,49,
%U 52,48,55,46,51,53,56,54,57,60,58,62,59,66,61,64,63,65,71,70,67,69,68,72,74,73,77,79
%N a(0) = 0; for n > 0, a(n) is the least positive integer not occurring earlier such that the digits in a(n-1)*a(n) are all distinct.
%C The sequence is finite, the 71782nd term being a(71781) = 50005 beyond which no number exists that has not occurred earlier such that 50005*a(n) has distinct digits. The maximum term is a(71428) = 175446.
%H Scott R. Shannon, <a href="/A338466/a338466.png">Image of the 71782 terms</a>. The green line is a(n) = n.
%e a(1) = 1 as a(0)*1 = 0*1 = 0 which has one distinct digit 0.
%e a(10) = 10 as a(9)*10 = 9*10 = 90 which has two distinct digits 9 and 0.
%e a(11) = 12 as a(10)*12 = 10*12 = 120 which has three distinct digits. Note that 11 is the first skipped number as 10*11 = 110 which has 1 as a duplicate digit.
%e a(12) = 11 as a(11)*11 = 12*11 = 132 which has three distinct digits.
%Y Cf. A342382, A010784, A043537, A043096, A276633, A002378.
%K nonn,base,fini,look
%O 0,3
%A _Scott R. Shannon_, Mar 09 2021
%E Offset corrected by _N. J. A. Sloane_, Jun 16 2021