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 A221697 Numbers n such that largest digit of all divisors of n is 2. 2
 2, 22, 121, 202, 211, 1021, 1201, 2011, 2111, 2221, 2222, 10201, 10211, 12011, 12101, 12211, 12221, 20011, 20021, 20101, 20201, 20222, 21001, 21011, 21101, 21121, 21211, 21221, 22111, 22121, 101021, 101221, 102001, 102101, 102121, 110221, 111121, 111211, 111221, 112111, 112121 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Also numbers n such that largest digit of concatenation of all divisors (A037278) of n is 2. Numbers n such that A209928(n) = 2. Union of A221698 and A106100. LINKS EXAMPLE Number 10201 is in sequence because largest digit of all divisors of 10201 (1, 101, 10201) is 2. MAPLE isA221697 := proc(n)       local dgs, d;       dgs := {} ;     for d in numtheory[divisors](n) do         dgs := dgs union convert(convert(d, base, 10), set) ;     end do:     if max(op(dgs)) = 2 then         true;     else         false;     end if; end proc: for n from 2 to 112121 do     if isA221697(n) then         printf("%d, ", n) ;     end if; end do: # R. J. Mathar, Jan 30 2013 MATHEMATICA Select[Range[115000], Max[Flatten[IntegerDigits/@Divisors[#]]]==2&] (* Harvey P. Dale, Dec 15 2014 *) CROSSREFS Cf. A209928 (largest digit of all divisors of n), A221698. Sequence in context: A325948 A216801 A083833 * A292452 A292732 A255866 Adjacent sequences:  A221694 A221695 A221696 * A221698 A221699 A221700 KEYWORD nonn,base AUTHOR Jaroslav Krizek, Jan 22 2013, corrected Jan 29 2013 STATUS approved

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Last modified September 22 11:29 EDT 2020. Contains 337289 sequences. (Running on oeis4.)