A284062 Numbers whose smallest decimal digit is 1.

1, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 31, 41, 51, 61, 71, 81, 91, 111, 112, 113, 114, 115, 116, 117, 118, 119, 121, 122, 123, 124, 125, 126, 127, 128, 129, 131, 132, 133, 134, 135, 136, 137, 138, 139, 141, 142, 143, 144, 145, 146, 147, 148, 149, 151, 152

Offset: 1

Author

Jaroslav Krizek, Mar 19 2017

Keywords

• nonn
• base

Comments

Numbers k such that A054054(k) = 1.

Prime terms are in A106101.

Crossrefs

Cf. Sequences of numbers whose smallest decimal digit is k (for k = 0..9): A011540 (k = 0), this sequence (k = 1), A284063 (k = 2), A284064 (k = 3), A284065 (k = 4), A284066 (k = 5), A284067 (k = 6), A284068 (k = 7), A284069 (k = 8), A002283 (k = 9).

Programs

Magma

[n: n in [1..100000] | Minimum(Setseq(Set(Sort(&cat[Intseq(n)])))) eq 1]

Mathematica

Select[Range[300], Min[IntegerDigits[#]]==1 &] (* Indranil Ghosh, Mar 19 2017 *)

PARI

for(n=1, 300, if(vecmin(digits(n))==1, print1(n,", "))) \\ Indranil Ghosh, Mar 19 2017

Python

from sympy.ntheory.factor_ import digits
print([n for n in range(1, 301) if min(digits(n)[1:])==1]) # Indranil Ghosh, Mar 19 2017