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URL: https://oeis.org/A338466

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A338466
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.
6
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, 27, 25, 29, 28, 30, 31, 33, 32, 39, 34, 37, 35, 36, 38, 40, 41, 43, 42, 45, 44, 47, 50, 49, 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
OFFSET
0,3
COMMENTS
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.
LINKS
Scott R. Shannon, Image of the 71782 terms. The green line is a(n) = n.
EXAMPLE
a(1) = 1 as a(0)*1 = 0*1 = 0 which has one distinct digit 0.
a(10) = 10 as a(9)*10 = 9*10 = 90 which has two distinct digits 9 and 0.
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.
a(12) = 11 as a(11)*11 = 12*11 = 132 which has three distinct digits.
CROSSREFS
KEYWORD
nonn,base,fini,look
AUTHOR
Scott R. Shannon, Mar 09 2021
EXTENSIONS
Offset corrected by N. J. A. Sloane, Jun 16 2021
STATUS
approved