

A185867


Numbers m whose decimal digits are a subsequence of the decimal digits of k*m for some 1 < k < 10.


0



2, 4, 5, 6, 8, 15, 18, 20, 25, 35, 40, 45, 50, 60, 75, 80, 125, 150, 175, 180, 200, 225, 250, 275, 350, 375, 400, 450, 475, 500, 575, 600, 625, 675, 750, 800, 875, 1125, 1250, 1375, 1500, 1625, 1750, 1800, 1875
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OFFSET

1,1


COMMENTS

Are there finitely many nonmultiples of 10 in this sequence? a(72) = 7875 seems to be the last one.  Charles R Greathouse IV, Feb 08 2011


LINKS



EXAMPLE

15 is a term because 15*7 = 105, and 105 can be formed from 15 by inserting the digit 0 in the middle.


PROG

(PARI) sub(v, u)=my(j=1); if(#v==#u, return(0)); for(i=1, #v, if(v[i]!=u[j], if(i!=j, return(0)), j++)); 1
isA185867(n)=my(N=eval(Vec(Str(n)))); for(k=2, 9, if(sub(eval(Vec(Str(n*k))), N), return(k))); 0


CROSSREFS



KEYWORD

nonn,base


AUTHOR



EXTENSIONS



STATUS

approved



