A284069 Numbers whose smallest decimal digit is 8.

8, 88, 89, 98, 888, 889, 898, 899, 988, 989, 998, 8888, 8889, 8898, 8899, 8988, 8989, 8998, 8999, 9888, 9889, 9898, 9899, 9988, 9989, 9998, 88888, 88889, 88898, 88899, 88988, 88989, 88998, 88999, 89888, 89889, 89898, 89899, 89988, 89989, 89998, 89999, 98888

Offset

1,1

Comments

Numbers n such that A054054(n) = 8.

Prime terms are in A020472. - Corrected by Robert Israel, Apr 05 2017

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Formula

From Robert Israel, Apr 05 2017: (Start)

a(2*j+2^(m+1)-m-3) = 10*a(j+2^m-m-1)+8 for j=1..2^m-1.

a(2*j+2^(m+1)-m-2) = 10*a(j+2^m-m-1)+9 for j=1..2^m-1.

a(2^(m+1)-m-2) = 10^m-2. (End)

Maple

F:= proc(d) local r; # to get all terms with d digits
r:= 8*(10^d-1)/9;
op(sort(convert(map(t -> r + add(10^(j-1), j=t), combinat:-powerset(d) minus {{$1..d}}), list)))
end proc:
map(F, [$1..5]); # Robert Israel, Apr 05 2017

Mathematica

Flatten@ Table[ Most[ FromDigits /@ Tuples[{8, 9}, k]], {k, 5}] (* Giovanni Resta, Mar 24 2017 *)

Prog

(Magma) [n: n in [1..100000] | Minimum(Setseq(Set(Sort(&cat[Intseq(n)])))) eq 8]
(PARI) isok(n) = vecmin(digits(n)) == 8; \\ Michel Marcus, Mar 25 2017
(Python)
print([n for n in range(8, 10**6) if min(str(n))=='8']) # Indranil Ghosh, Apr 06 2017

Crossrefs

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).

Cf. A020472, A054054.

Sequence in context: A246512 A366233 A248471 * A292458 A292738 A035133

Adjacent sequences: A284066 A284067 A284068 * A284070 A284071 A284072

Keyword

nonn,base

Author

Jaroslav Krizek, Mar 24 2017

Status

approved