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A039938 Smallest k for which k, 2k, ... nk all contain the digit 7. 12
7, 37, 237, 1789, 4357, 14379, 19587, 93957, 189572, 189572, 189597, 189597, 189597, 1234397, 1839597, 1958798, 1983957, 1983957, 1983957, 1983957, 1983957, 1983957, 3978594, 11983957, 19596487, 29195397, 29195397, 29195397 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
a(2)=37 since 37 and 74 contain a 7.
MATHEMATICA
Table[SelectFirst[Range[10^6], Times @@ Boole@ Map[DigitCount[#, 10, 7] > 0 &, # Range@ n] > 0 &], {n, 12}] (* Michael De Vlieger, Apr 27 2017, Version 10 *)
CROSSREFS
Sequence in context: A339686 A144496 A025012 * A285846 A102760 A332906
KEYWORD
base,nonn
AUTHOR
EXTENSIONS
More terms from Patrick De Geest, Oct 15 1999
STATUS
approved

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Last modified March 29 01:36 EDT 2024. Contains 371264 sequences. (Running on oeis4.)