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A284069 Numbers whose smallest decimal digit is 8.

%I A284069 #38 Sep 08 2022 08:46:19
%S A284069 8,88,89,98,888,889,898,899,988,989,998,8888,8889,8898,8899,8988,8989,
%T A284069 8998,8999,9888,9889,9898,9899,9988,9989,9998,88888,88889,88898,88899,
%U A284069 88988,88989,88998,88999,89888,89889,89898,89899,89988,89989,89998,89999,98888
%N A284069 Numbers whose smallest decimal digit is 8.
%C A284069 Numbers n such that A054054(n) = 8.
%C A284069 Prime terms are in A020472. - Corrected by _Robert Israel_, Apr 05 2017
%H A284069 Robert Israel, <a href="/A284069/b284069.txt">Table of n, a(n) for n = 1..10000</a>
%F A284069 From _Robert Israel_, Apr 05 2017: (Start)
%F A284069 a(2*j+2^(m+1)-m-3) = 10*a(j+2^m-m-1)+8 for j=1..2^m-1.
%F A284069 a(2*j+2^(m+1)-m-2) = 10*a(j+2^m-m-1)+9 for j=1..2^m-1.
%F A284069 a(2^(m+1)-m-2) = 10^m-2. (End)
%p A284069 F:= proc(d) local r; # to get all terms with d digits
%p A284069 r:= 8*(10^d-1)/9;
%p A284069 op(sort(convert(map(t -> r + add(10^(j-1),j=t), combinat:-powerset(d) minus {{$1..d}}),list)))
%p A284069 end proc:
%p A284069 map(F, [$1..5]); # _Robert Israel_, Apr 05 2017
%t A284069 Flatten@ Table[ Most[ FromDigits /@ Tuples[{8,9}, k]], {k,5}] (* _Giovanni Resta_, Mar 24 2017 *)
%o A284069 (Magma) [n: n in [1..100000] | Minimum(Setseq(Set(Sort(&cat[Intseq(n)])))) eq 8]
%o A284069 (PARI) isok(n) = vecmin(digits(n)) == 8; \\ _Michel Marcus_, Mar 25 2017
%o A284069 (Python)
%o A284069 print([n for n in range(8, 10**6) if min(str(n))=='8']) # _Indranil Ghosh_, Apr 06 2017
%Y A284069 Cf. Sequences of numbers whose smallest decimal digit is k (for k = 0..9): A011540 (k = 0), A284062 (k = 1), A284063 (k = 2), A284064 (k = 3), A284065 (k = 4), A284066 (k = 5), A284067 (k = 6), A284068 (k = 7), this sequence (k = 8), A002283 (k = 9).
%Y A284069 Cf. A020472, A054054.
%K A284069 nonn,base
%O A284069 1,1
%A A284069 _Jaroslav Krizek_, Mar 24 2017