cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 58 results. Next

A226778 Numbers having no common divisor > 1 with their reversal in decimal representation (see A043537).

Original entry on oeis.org

1, 10, 13, 14, 16, 17, 19, 23, 25, 29, 31, 32, 34, 35, 37, 38, 41, 43, 47, 49, 52, 53, 56, 58, 59, 61, 65, 67, 71, 73, 74, 76, 79, 83, 85, 89, 91, 92, 94, 95, 97, 98, 100, 103, 104, 106, 107, 109, 112, 113, 115, 116, 118, 119, 122, 124, 125, 127, 128, 130
Offset: 1

Views

Author

Reinhard Zumkeller, Jun 18 2013

Keywords

Comments

A055483(a(n)) = 1.

Crossrefs

Cf. A043537, A055483, A071249 (complement).

Programs

  • Haskell
    a226778 n = a226778_list !! (n-1)
    a226778_list = filter ((== 1) . a055483) [1..]
    
  • Mathematica
    Select[Range[130], GCD[#, FromDigits[Reverse[IntegerDigits[#]]]] == 1 &] (* Jayanta Basu, Jul 24 2013 *)
    Select[Range[150],Intersection[Divisors[#],Divisors[IntegerReverse[#]]] == {1}&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Jul 07 2020 *)
  • PARI
    isok(n) = gcd(n, subst(Pol(Vecrev(digits(n))), x, 10)) == 1; \\ Michel Marcus, Jul 02 2015
    
  • PARI
    is(n)=gcd(fromdigits(Vecrev(digits(n))), n)==1 \\ Charles R Greathouse IV, Aug 25 2016

A055642 Number of digits in the decimal expansion of n.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3
Offset: 0

Views

Author

Henry Bottomley, Jun 06 2000

Keywords

Comments

From Hieronymus Fischer, Jun 08 2012: (Start)
For n > 0 the first differences of A117804.
The total number of digits necessary to write down all the numbers 0, 1, 2, ..., n is A117804(n+1). (End)
Here a(0) = 1, but a different common convention is to consider that the expansion of 0 in any base b > 0 has 0 terms and digits. - M. F. Hasler, Dec 07 2018

Examples

			Examples:
999: 1 + floor(log_10(999)) = 1 + floor(2.x) = 1 + 2 = 3 or
      ceiling(log_10(999+1)) = ceiling(log_10(1000)) = ceiling(3) = 3;
1000: 1 + floor(log_10(1000)) = 1 + floor(3) = 1 + 3 = 4 or
      ceiling(log_10(1000+1)) = ceiling(log_10(1001)) = ceiling(3.x) = 4;
1001: 1 + floor(log_10(1001)) = 1 + floor(3.x) = 1 + 3 = 4 or
      ceiling(log_10(1001+1)) = ceiling(log_10(1002)) = ceiling(3.x) = 4;
		

Crossrefs

Programs

  • Haskell
    a055642 :: Integer -> Int
    a055642 = length . show  -- Reinhard Zumkeller, Feb 19 2012, Apr 26 2011
    
  • Magma
    [ #Intseq(n): n in [0..105] ];   //  Bruno Berselli, Jun 30 2011
    (Common Lisp) (defun A055642 (n) (if (zerop n) 1 (floor (log n 10)))) ; James Spahlinger, Oct 13 2012
    
  • Maple
    A055642 := proc(n)
            max(1,ilog10(n)+1) ;
    end proc:  # R. J. Mathar, Nov 30 2011
  • Mathematica
    Join[{1}, Array[ Floor[ Log[10, 10# ]] &, 104]] (* Robert G. Wilson v, Jan 04 2006 *)
    Join[{1},Table[IntegerLength[n],{n,104}]]
    IntegerLength[Range[0,120]] (* Harvey P. Dale, Jul 02 2016 *)
  • PARI
    a(n)=#Str(n) \\ M. F. Hasler, Nov 17 2008
    
  • PARI
    A055642(n)=logint(n+!n,10)+1 \\ Increasingly faster than the above, for larger n. (About twice as fast for n ~ 10^7.) - M. F. Hasler, Dec 07 2018
    
  • Python
    def a(n): return len(str(n))
    print([a(n) for n in range(121)]) # Michael S. Branicky, May 10 2022
    
  • Python
    def A055642(n): # Faster than len(str(n)) from ~ 50 digits on
        L = math.log10(n or 1)
        if L.is_integer() and 10**int(L)>n: return int(L or 1)
        return int(L)+1  # M. F. Hasler, Apr 08 2024

Formula

a(A046760(n)) < A050252(A046760(n)); a(A046759(n)) > A050252(A046759(n)). - Reinhard Zumkeller, Jun 21 2011
a(n) = A196563(n) + A196564(n).
a(n) = 1 + floor(log_10(n)) = 1 + A004216(n) = ceiling(log_10(n+1)) = A004218(n+1), if n >= 1. - Daniel Forgues, Mar 27 2014
a(A046758(n)) = A050252(A046758(n)). - Reinhard Zumkeller, Jun 21 2011
a(n) = A117804(n+1) - A117804(n), n > 0. - Hieronymus Fischer, Jun 08 2012
G.f.: g(x) = 1 + (1/(1-x))*Sum_{j>=0} x^(10^j). - Hieronymus Fischer, Jun 08 2012
a(n) = A262190(n) for n < 100; a(A262198(n)) != A262190(A262198(n)). - Reinhard Zumkeller, Sep 14 2015

A010784 Numbers with distinct decimal digits.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 102, 103, 104, 105, 106, 107, 108, 109, 120
Offset: 1

Views

Author

Keywords

Comments

More than the usual number of terms are displayed in order to show the difference from some closely related sequences.
Also: a(1) = 0; a(n) = Min{x integer | x > a(n-1) and all digits to base 10 are distinct}.
This sequence is finite: a(8877691) = 9876543210 is the last term; a(8877690) = 9876543201. The largest gap between two consecutive terms before a(249999) = 2409653 is 104691, as a(175289) = 1098765, a(175290) = 1203456. - Reinhard Zumkeller, Jun 23 2001
Complement of A109303. - David Wasserman, May 21 2008
For the analogs in other bases b, search for "xenodromes." A001339(b-1) is the number of base b xenodromes for b >= 2. - Rick L. Shepherd, Feb 16 2013
A073531 gives the number of positive n-digit numbers in this sequence. Note that it does not count 0. - T. D. Noe, Jul 09 2013
Can be seen as irregular table whose n-th row holds the n-digit terms; length of row n is then A073531(n) = 9*9!/(10-n)! except for n = 1 where we have 10 terms, unless 0 is considered to belong to a row 0. - M. F. Hasler, Dec 10 2018

Crossrefs

Subsequence of A043096.
Cf. A109303, A029740 (odds), A029741 (evens), A029743 (primes), A001339.

Programs

  • Haskell
    a010784 n = a010784_list !! (n-1)
    a010784_list = filter ((== 1) . a178788) [1..]
    -- Reinhard Zumkeller, Sep 29 2011
    
  • Mathematica
    Select[Range[0,100], Max[DigitCount[#]] == 1 &] (* Harvey P. Dale, Apr 04 2013 *)
  • PARI
    is(n)=my(v=vecsort(digits(n)));v==vecsort(v,,8) \\ Charles R Greathouse IV, Sep 17 2012
    
  • PARI
    select( is(n)=!n||#Set(digits(n))==logint(n,10)+1, [0..120]) \\ M. F. Hasler, Dec 10 2018
    
  • PARI
    apply( A010784_row(n,L=List(if(n>1,[])))={forvec(d=vector(n,i,[0,9]),forperm(d,p,p[1]&&listput(L,fromdigits(Vec(p)))),2);Set(L)}, [1..2]) \\ A010784_row(n) returns all terms with n digits. - M. F. Hasler, Dec 10 2018
    
  • Python
    A010784_list = [n for n in range(10**6) if len(set(str(n))) == len(str(n))] # Chai Wah Wu, Oct 13 2019
    
  • Python
    # alternate for generating full sequence
    from itertools import permutations
    afull = [0] + [int("".join(p)) for d in range(1, 11) for p in permutations("0123456789", d) if p[0] != "0"]
    print(afull[:100]) # Michael S. Branicky, Aug 04 2022
    
  • Scala
    def hasDistinctDigits(n: Int): Boolean = {
      val numerStr = n.toString
      val digitSet = numerStr.split("").toSet
      numerStr.length == digitSet.size
    }
    (0 to 99).filter(hasDistinctDigits) // Alonso del Arte, Jan 09 2020

Formula

A178788(a(n)) = 1; A178787(a(n)) = n; A043537(a(n)) = A055642(a(n)). - Reinhard Zumkeller, Jun 30 2010
A107846(a(n)) = 0. - Reinhard Zumkeller, Jul 09 2013

Extensions

Offset changed to 1 and first comment adjusted by Reinhard Zumkeller, Jun 14 2010

A047726 Number of different numbers that are formed by permuting digits of n.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 1, 3, 3, 6
Offset: 1

Views

Author

Keywords

Comments

The minimum value of a(A171102(n)) is 10*9!. - Altug Alkan, Jul 08 2016

Examples

			From 102 we get 102, 120, 210, 201, 12 and 21, so a(102)=6.
From 33950 with 5 digits, one '0', two '3', one '5' and one '9', we get 5! / (1! * 2! * 1! * 1!) = 60 different numbers and a(33950) = 60.  - _Bernard Schott_, Oct 20 2019
		

Crossrefs

Cf. A055098. Identical to A043537 and A043562 for n<100.
Cf. A179239. - Aaron Dunigan AtLee, Jul 14 2010

Programs

  • Haskell
    import Data.List (permutations, nub)
    a047726 n = length $ nub $ permutations $ show n
    -- Reinhard Zumkeller, Jul 26 2011
    
  • Maple
    f:= proc(n) local L;
      L:= convert(n,base,10);
      nops(L)!/mul(numboccur(i,L)!,i=0..9);
    end proc:
    map(f, [$1..1000]); # Robert Israel, Jul 08 2016
  • Mathematica
    pd[n_]:=Module[{p=Permutations[IntegerDigits[n]]},Length[Union [FromDigits/@p]]]; pd/@Range[120]  (* Harvey P. Dale, Mar 22 2011 *)
  • PARI
    a(n)=n=eval(Vec(Str(n)));(#n)!/prod(i=0,9,sum(j=1,#n,n[j]==i)!) \\ Charles R Greathouse IV, Sep 29 2011
    
  • PARI
    A047726(n)={local(c=Vec(0,10)); apply(d->c[d+1]++, digits(n)); logint(n*10,10)!/prod(i=1,10,c[i]!)} \\ M. F. Hasler, Oct 18 2019

Formula

a(n) << n / (log_10 n)^4.5 by Stirling's approximation. - Charles R Greathouse IV, Sep 29 2011
a(n) = A000142(A055642(n))/Product_{k=0..9} A000142(A100910(n,k)). - Robert Israel, Jul 08 2016

Extensions

Corrected by Henry Bottomley, Apr 19 2000

A178788 Characteristic function of numbers having distinct digits in their decimal representation.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1
Offset: 0

Views

Author

Reinhard Zumkeller, Jun 30 2010

Keywords

Comments

a(A010784(n)) = 1; a(A109303(n)) = 0;
first differences of A178787.
a(n) <= A196368(n).
a(n) = 0 for n > 9*9!. - Hieronymus Fischer, Feb 02 2013

Programs

  • Haskell
    import Data.List (nub)
    a178788 n = fromEnum $ nub (show n) == show n
    -- Reinhard Zumkeller, Sep 25 2011
  • Mathematica
    lst = {}; Do[If[Select[Tally[IntegerDigits[n]][[All, 2]], # > 1 &] == {}, AppendTo[lst, 1], AppendTo[lst, 0]], {n, 0, 104}]; lst (* Arkadiusz Wesolowski, May 10 2012 *)

Formula

a(n) = 0^(A055642(n)-A043537(n)).

A137580 Number of distinct digits in decimal representation of n!.

Original entry on oeis.org

1, 1, 1, 1, 2, 3, 3, 3, 4, 5, 5, 6, 6, 5, 6, 7, 5, 9, 8, 8, 9, 7, 7, 10, 9, 8, 9, 10, 8, 9, 9, 10, 9, 10, 10, 10, 10, 10, 9, 10, 10, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10
Offset: 0

Views

Author

Reinhard Zumkeller, Jan 27 2008

Keywords

Examples

			n=12: 12! = 479001600 => a(12) = #{0,1,4,6,7,9} = 6.
		

Crossrefs

Programs

  • Haskell
    import Data.List (nub, sort)
    a137580 = length . nub . show . a000142
    -- Reinhard Zumkeller, Apr 08 2012
    
  • Mathematica
    Map[Length[Union[IntegerDigits[#]]] &, Table[n!, {n, 0, 79}]] (* Geoffrey Critzer, May 25 2013 *)
  • PARI
    A137580(n)=#Set(digits(n!)) \\ M. F. Hasler, May 04 2015

Formula

a(n) = A043537(A000142(n)).
a(n) < 10 iff A137579(n) = 0.
a(A182049(n)) < 10. - Reinhard Zumkeller, Apr 08 2012

A031955 Numbers with exactly two distinct base-10 digits.

Original entry on oeis.org

10, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 100, 101, 110, 112, 113, 114, 115, 116, 117, 118, 119, 121, 122, 131, 133, 141, 144, 151, 155, 161, 166
Offset: 1

Views

Author

Keywords

Comments

The three-digit terms are given by A210666(1,...,244). For numbers with exactly two distinct (but unspecified) digits in other bases, see A031948-A031954. For numbers made of two *given* digits, see A007088 (digits 0 & 1), A007931 (digits 1 & 2), A032810 (digits 2 & 3), A032834 (digits 3 & 4), A256290 (digits 4 & 5), A256291 (digits 5 & 6), A256292 (digits 6 & 7), A256340 (digits 7 & 8), A256341 (digits 8 & 9), and A032804-A032816 (in other bases). - M. F. Hasler, Apr 04 2015
A235154 is a subsequence. - Altug Alkan, Dec 03 2015
A235717 is a subsequence. - Robert Israel, Dec 03 2015

Crossrefs

Programs

  • Haskell
    a031955 n = a031955_list !! (n-1)
    a031955_list = filter ((== 2) . a043537) [0..]
    -- Reinhard Zumkeller, Feb 05 2012
    
  • Maple
    M:= 5: # to get all terms < 10^M
    sort([seq(seq(seq(seq(add(10^(m-j)*`if`(member(j,S2),d2,d1),j=1..m)  ,
      S2 = combinat:-powerset({$2..m}) minus {{}}),
      d2 = {$0..9} minus {d1}), d1 = 1..9), m=2..M)]); # Robert Israel, Dec 03 2015
  • Mathematica
    Select[Range@ 166, Length@ Union@ IntegerDigits@ # == 2 &] (* Michael De Vlieger, Dec 03 2015 *)
  • PARI
    is_A031955(n)=#Set(digits(n))==2 \\ M. F. Hasler, Apr 04 2015
    
  • Python
    def ok(n): return len(set(str(n))) == 2
    print(list(filter(ok, range(167)))) # Michael S. Branicky, Oct 12 2021

Formula

A043537(a(n)) = 2. - Reinhard Zumkeller, Dec 03 2009

Extensions

Name edited by Charles R Greathouse IV, Feb 13 2017

A095048 Number of distinct digits needed to write all positive divisors of n in decimal representation.

Original entry on oeis.org

1, 2, 2, 3, 2, 4, 2, 4, 3, 4, 1, 5, 2, 4, 3, 5, 2, 6, 2, 5, 4, 2, 3, 6, 3, 4, 5, 5, 3, 6, 2, 6, 2, 5, 4, 7, 3, 5, 3, 6, 2, 6, 3, 3, 5, 5, 3, 6, 4, 4, 4, 6, 3, 9, 2, 7, 5, 5, 3, 7, 2, 4, 6, 6, 4, 4, 3, 7, 5, 7, 2, 8, 3, 5, 5, 8, 2, 7, 3, 7, 6, 4, 3, 7, 4, 6, 6, 4, 3, 9, 4, 6, 3, 5, 3, 7, 3, 6, 3, 5, 2, 8
Offset: 1

Views

Author

Reinhard Zumkeller, May 28 2004

Keywords

Comments

a(n) <= 10, a(A095050(n)) = 10.
a(A206159(n)) <= 2. - Reinhard Zumkeller, Feb 05 2012
Almost all (in the sense of natural density) terms of this sequence are equal to 10. - Charles R Greathouse IV, Nov 16 2022

Examples

			Set of divisors of n=10: {1,2,5,10}, therefore a(10) = #{0,1,2,5} = 4.
Set of divisors of n=16: {1,2,4,8,16}, therefore a(16)=#{1,2,4,6,8} = 5.
		

Crossrefs

Programs

  • Haskell
    import Data.List (group, sort)
    a095048 = length . group . sort . concatMap show . a027750_row
    -- Reinhard Zumkeller, Feb 05 2012
    
  • Maple
    A095048 := proc(n)
        local digset ;
        digset := {} ;
        for d in numtheory[divisors](n) do
            digset := digset union convert(convert(d,base,10),set) ;
        end do:
        nops(digset) ;
    end proc:
    seq(A095048(n),n=1..80) ; # R. J. Mathar, May 13 2022
  • PARI
    a(n) = my(d = divisors(n), s = 0); for(i = 1, #d, v = digits(d[i]); for(j = 1, #v, s = bitor(s, 1<David A. Corneth, Nov 16 2022
  • Python
    from sympy import divisors
    def a(n):
        s = set("1"+str(n))
        if len(s) == 10: return 10
        for d in divisors(n, generator=True):
            s |= set(str(d))
            if len(s) == 10: return 10
        return len(s)
    print([a(n) for n in range(1, 99)]) # Michael S. Branicky, Nov 16 2022
    

A109303 Numbers k with at least one duplicate base-10 digit (A107846(k) > 0).

Original entry on oeis.org

11, 22, 33, 44, 55, 66, 77, 88, 99, 100, 101, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 121, 122, 131, 133, 141, 144, 151, 155, 161, 166, 171, 177, 181, 188, 191, 199, 200, 202, 211, 212, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 232, 233, 242
Offset: 1

Views

Author

Rick L. Shepherd, Jun 24 2005

Keywords

Comments

Complement of A010784, numbers with distinct base-10 digits, so all numbers greater than 9876543210 (last term of A010784) are terms. a(263)=1001 is the first term not also a term of A044959; a(264)=1002 is the first term not also a term of A084050. The terms of A044959 greater than 9 are a subsequence. The terms of A084050 greater than 90 are a subsequence.
A178788(a(n)) = 0; A178787(a(n)) = A178787(a(n)-1); A043537(a(n)) < A109303(a(n)). - Reinhard Zumkeller, Jun 30 2010
A227362(a(n)) < a(n). - Reinhard Zumkeller, Jul 09 2013

Crossrefs

Cf. A010784 (numbers with distinct digits), A044959 (numbers with no two equally numerous digits), A084050 (numbers with a palindromic permutation of digits), A107846 (number of duplicate digits of n). Also see A062813, which gives the largest number in each base containing all distinct digits.

Programs

  • Haskell
    a109303 n = a109303_list !! (n-1)
    a109303_list = filter ((> 0) . a107846) [0..]
    -- Reinhard Zumkeller, Jul 09 2013
    
  • Mathematica
    Select[Range[300], Max[DigitCount[#]] > 1 &] (* Harvey P. Dale, Jan 14 2011 *)
  • Python
    def ok(n): s = str(n); return len(set(s)) < len(s)
    print([k for k in range(243) if ok(k)]) # Michael S. Branicky, Nov 22 2021

A130694 Exponents of powers of 2 that contain all ten digits.

Original entry on oeis.org

68, 70, 79, 82, 84, 87, 88, 89, 94, 95, 96, 97, 98, 100, 101, 103, 104, 105, 106, 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, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144
Offset: 1

Views

Author

Greg Dresden, Jul 10 2007

Keywords

Comments

It is believed that every power of 2 beyond 2^86 contains the digit 0.
For k in {51,67,72,76,81,86}, 2^k contains all nonzero digits, but does not contain 0. - Dimiter Skordev, Oct 05 2021

Examples

			2^68 = 295147905179352825856.
		

Crossrefs

Complement of A130696.

Programs

  • Mathematica
    A2 := {}; Do[If[Length[Union[ IntegerDigits[2^ n]]] == 10, A2 = Join[A2, {n}]], {n, 1, 200}]; Print[A2]
    Select[Range[200],Min[DigitCount[2^#]]>0&] (* Harvey P. Dale, Aug 03 2019 *)
  • PARI
    is_A130694(n)=9<#Set(Vec(Str(1<M. F. Hasler, Aug 25 2012

Formula

A043537(A000079(a(n))) = 10. - Reinhard Zumkeller, Jul 29 2007
a(n) = n + 91 for n >= 78 (conjectured). - Chai Wah Wu, Jan 27 2020

Extensions

Displayed terms double-checked by M. F. Hasler, Aug 25 2012
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