login
This site is supported by donations to The OEIS Foundation.

 

Logo

Thanks to everyone who made a donation during our annual appeal!
To see the list of donors, or make a donation, see the OEIS Foundation home page.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A011531 Numbers that contain a digit 1 in their decimal representation. 62
1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 31, 41, 51, 61, 71, 81, 91, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A121042(a(n)) = 1. - Reinhard Zumkeller, Jul 21 2006

See A043493 for numbers that contain a single digit '1'. A subsequence of numbers having a digit that divides all other digits, A263314. - M. F. Hasler, Jan 11 2016

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Index entries for 10-automatic sequences.

MAPLE

M:= 3: # to get all terms of up to M digits

B:= {1}: A:= {1}:

for i from 2 to M do

   B:= map(t -> seq(10*t+j, j=0..9), B) union

      {seq(10*x+1, x=2*10^(i-2)..10^(i-1)-1)}:

   A:= A union B;

od:

sort(convert(A, list)); # Robert Israel, Jan 10 2016

# second program:

A011531 := proc(n)

    if n = 1 then

        1;

    else

        for a from procname(n-1)+1 do

            if nops(convert(convert(a, base, 10), set) intersect {1}) > 0 then

                return a;

            end if;

        end do:

    end if;

end proc: # R. J. Mathar, Jul 31 2016

MATHEMATICA

Select[Range[600] - 1, DigitCount[#, 10, 1]>0 &] (* Vincenzo Librandi, Jan 11 2016 *)

PROG

(Haskell)

a011531 n = a011531_list !! (n-1)

a011531_list = filter ((elem '1') . show) [0..]

-- Reinhard Zumkeller, Feb 05 2012

(PARI) is_A011531(n)=setsearch(Set(digits(n)), 1) \\ M. F. Hasler, Jan 10 2016

(MAGMA) [n: n in [0..500] | 1 in Intseq(n) ]; // Vincenzo Librandi, Jan 11 2016

CROSSREFS

Cf. A121041, A121022, A121023, A121024, A121025, A121026, A121027, A121028, A121029, A121030, A121031, A121032, A121033, A121034, A121035, A121036, A121037, A121038, A121039, A121040.

Cf. A062634, a subsequence.

Cf. A052383 (complement).

Sequence in context: A069715 A248499 A008716 * A257946 A070839 A161561

Adjacent sequences:  A011528 A011529 A011530 * A011532 A011533 A011534

KEYWORD

nonn,base

AUTHOR

N. J. A. Sloane.

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 15 20:47 EST 2019. Contains 319184 sequences. (Running on oeis4.)