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 1-9 of 9 results.

A155147 Numbers k such that k^3 has exactly 4 different digits.

Original entry on oeis.org

12, 13, 16, 17, 18, 19, 21, 23, 25, 26, 28, 31, 33, 34, 37, 39, 42, 43, 44, 45, 46, 50, 53, 56, 58, 60, 64, 67, 68, 74, 77, 78, 79, 80, 81, 83, 86, 90, 91, 95, 98, 99, 106, 111, 114, 117, 121, 122, 132, 140, 142, 146, 150, 157, 160, 163, 164, 171, 172, 175, 177, 179
Offset: 1

Views

Author

Dmitry Kamenetsky, Jan 21 2009

Keywords

Crossrefs

Cf. A155146.

Programs

  • Maple
    a := proc (n) if nops(convert(convert(n^3, base, 10), set)) = 4 then n else end if end proc: seq(a(n), n = 1 .. 220); # Emeric Deutsch, Jan 26 2009

Extensions

Extended by Emeric Deutsch, Jan 26 2009

A235807 Numbers n such that n^3 has one or more occurrences of exactly five different digits.

Original entry on oeis.org

22, 24, 27, 29, 32, 35, 38, 41, 47, 48, 49, 51, 52, 54, 55, 57, 61, 63, 65, 71, 72, 82, 85, 87, 89, 94, 96, 102, 103, 104, 105, 108, 109, 119, 120, 123, 125, 126, 127, 130, 133, 134, 136, 137, 138, 141, 143, 144, 149, 152, 153, 154, 155, 158, 162, 165, 167
Offset: 1

Views

Author

Colin Barker, Jan 19 2014

Keywords

Examples

			22 is in the sequence because 22^3 = 10648, which contains exactly five different digits: 0, 1, 4, 6, 8.
87 is in the sequence because 87^3 = 658503, which contains exactly five different digits: 0, 3, 5, 6, 8.
		

Crossrefs

Programs

  • Magma
    [n: n in [0..200] | #Set(Intseq(n^3)) eq 5]; // Bruno Berselli, Jan 19 2014
    
  • Mathematica
    Select[Range[200], Length[Union[IntegerDigits[#^3]]] == 5 &] (* Bruno Berselli, Jan 19 2014 *)
  • PARI
    s=[]; for(n=1, 200, if(#vecsort(eval(Vec(Str(n^3))),,8)==5, s=concat(s, n))); s
    
  • Python
    A235807_list, m = [], [6, -6, 1, 0]
    for n in range(1,10**5+1):
        for i in range(3):
            m[i+1] += m[i]
        if len(set(str(m[-1]))) == 5:
            A235807_list.append(n) # Chai Wah Wu, Nov 05 2014

A235811 Numbers n such that n^3 has one or more occurrences of exactly nine different digits.

Original entry on oeis.org

1018, 1028, 1112, 1452, 1475, 1484, 1531, 1706, 1721, 1733, 1818, 1844, 1895, 1903, 2008, 2033, 2208, 2214, 2217, 2223, 2257, 2274, 2277, 2327, 2329, 2336, 2354, 2394, 2403, 2524, 2525, 2589, 2647, 2686, 2691, 2694, 2727, 2733, 2784, 2842, 2866, 2884, 2890
Offset: 1

Views

Author

Colin Barker, Jan 19 2014

Keywords

Examples

			1018 is in the sequence because 1018^3 = 1054977832, which contains exactly nine different digits.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[3000],Count[DigitCount[#^3],0]==1&] (* Harvey P. Dale, Dec 17 2021 *)
  • PARI
    s=[]; for(n=1, 3000, if(#vecsort(eval(Vec(Str(n^3))),,8)==9, s=concat(s, n))); s
    
  • Python
    A235811_list, m = [], [6, -6, 1, 0]
    for n in range(1,10**4+1):
        for i in range(3):
            m[i+1] += m[i]
        if len(set(str(m[-1]))) == 9:
            A235811_list.append(n) # Chai Wah Wu, Nov 05 2014

A235808 Numbers k such that k^3 has one or more occurrences of exactly six different digits.

Original entry on oeis.org

59, 66, 69, 73, 75, 76, 84, 88, 93, 97, 107, 112, 113, 115, 116, 118, 124, 128, 129, 131, 139, 147, 148, 151, 156, 159, 161, 166, 168, 169, 174, 178, 181, 183, 184, 187, 189, 193, 194, 196, 207, 219, 226, 232, 234, 235, 236, 238, 240, 241, 246, 253, 255, 262
Offset: 1

Views

Author

Colin Barker, Jan 19 2014

Keywords

Examples

			59 is in the sequence because 59^3 = 205379, which contains exactly six different digits: 0, 2, 3, 5, 7, 9.
107 is in the sequence because 107^3 = 1225043, which contains exactly six different digits: 0, 1, 2, 3, 4, 5.
		

Crossrefs

Programs

  • Magma
    [n: n in [0..300] | #Set(Intseq(n^3)) eq 6]; // Bruno Berselli, Jan 19 2014
    
  • Mathematica
    Select[Range[300], Length[Union[IntegerDigits[#^3]]] == 6 &] (* Bruno Berselli, Jan 19 2014 *)
    Select[Range[300],Count[DigitCount[#^3],0]==4&] (* Harvey P. Dale, May 28 2025 *)
  • PARI
    s=[]; for(n=1, 300, if(#vecsort(eval(Vec(Str(n^3))),,8)==6, s=concat(s, n))); s
    
  • Python
    A235808_list, m = [], [6, -6, 1, 0]
    for n in range(1,10**4+1):
        for i in range(3):
            m[i+1] += m[i]
        if len(set(str(m[-1]))) == 6:
            A235808_list.append(n) # Chai Wah Wu, Nov 05 2014

A235809 Numbers k such that k^3 has one or more occurrences of exactly seven different digits.

Original entry on oeis.org

135, 145, 203, 221, 223, 225, 227, 233, 243, 244, 245, 247, 249, 254, 257, 265, 272, 273, 275, 276, 299, 313, 327, 329, 334, 338, 341, 345, 347, 352, 365, 366, 368, 382, 384, 388, 393, 395, 398, 403, 405, 409, 411, 412, 434, 439, 447, 452, 455, 473, 486, 493
Offset: 1

Views

Author

Colin Barker, Jan 19 2014

Keywords

Examples

			135 is in the sequence because 135^3 = 2460375, which contains exactly seven different digits.
		

Crossrefs

Programs

  • Magma
    [n: n in [0..1200] | #Set(Intseq(n^3)) eq 7]; // Vincenzo Librandi, Nov 07 2014
    
  • Mathematica
    Select[Range[500], Length[Union[IntegerDigits[#^3]]]==7&] (* Vincenzo Librandi, Nov 07 2014 *)
  • PARI
    s=[]; for(n=1, 600, if(#vecsort(eval(Vec(Str(n^3))),,8)==7, s=concat(s, n))); s
    
  • PARI
    for(n=0,10^3,if(#Set(digits(n^3))==7,print1(n,", "))); \\ Joerg Arndt, Nov 10 2014
    
  • Python
    from itertools import count, islice
    def A235809gen(): return filter(lambda n:len(set(str(n**3))) == 7,count(0))
    A235809_list = list(islice(A235809gen(),26)) # Chai Wah Wu, Dec 23 2021

A235810 Numbers n such that n^3 has one or more occurrences of exactly eight different digits.

Original entry on oeis.org

289, 297, 302, 319, 467, 494, 515, 557, 562, 595, 621, 623, 676, 682, 709, 712, 721, 862, 887, 909, 939, 945, 949, 963, 984, 987, 1012, 1015, 1016, 1025, 1029, 1043, 1049, 1065, 1075, 1087, 1104, 1106, 1107, 1114, 1118, 1132, 1137, 1154, 1161, 1167, 1178
Offset: 1

Views

Author

Colin Barker, Jan 19 2014

Keywords

Examples

			289 is in the sequence because 289^3 = 24137569, which contains exactly eight different digits.
		

Crossrefs

Programs

  • Magma
    [n: n in [0..1200] | #Set(Intseq(n^3)) eq 8]; // Vincenzo Librandi, Nov 07 2014
  • PARI
    s=[]; for(n=1, 1500, if(#vecsort(eval(Vec(Str(n^3))),,8)==8, s=concat(s, n))); s
    
  • Python
    A235810_list, m = [], [6, -6, 1, 0]
    for n in range(1,10**3+1):
        for i in range(3):
            m[i+1] += m[i]
        if len(set(str(m[-1]))) == 8:
            A235810_list.append(n) # Chai Wah Wu, Nov 05 2014
    

A247045 Triangle read by rows: T(n,k) = least number m > 0 such that m^k in base n contains exactly k distinct digits, 1 <= k <= n.

Original entry on oeis.org

1, 1, 2, 1, 3, 4, 1, 2, 3, 5, 1, 3, 3, 6, 12, 1, 3, 5, 7, 7, 15, 1, 3, 5, 9, 5, 17, 15, 1, 4, 5, 10, 9, 7, 11, 33, 1, 3, 5, 7, 11, 19, 14, 16, 53, 1, 4, 5, 6, 7, 13, 13, 14, 21, 36, 1, 4, 5, 7, 10, 8, 12, 12, 16, 42, 41, 1, 4, 6, 16, 11, 8, 19, 19, 16, 28, 35, 55, 1, 4, 6, 9, 9, 14, 10, 18, 14
Offset: 1

Views

Author

Derek Orr, Sep 10 2014

Keywords

Examples

			T(n,k) is given by (row n corresponds to base n):
1;
1, 2;
1, 3, 4;
1, 2, 3,  5;
1, 3, 3,  6, 12;
1, 3, 5,  7,  7, 15;
1, 3, 5,  9,  5, 17, 15;
1, 4, 5, 10,  9,  7, 11, 33;
1, 3, 5,  7, 11, 19, 14, 16, 53;
1, 4, 5,  6,  7, 13, 13, 14, 21, 36; (base 10)
1, 4, 5,  7, 10,  8, 12, 12, 16, 42, 41;
Example: T(7,3) = 5 means that 5 is the smallest number such that 5^3 in base 7 (which is 125 in base 7 = 236) has 3 distinct digits (2, 3, and 6).
		

Crossrefs

Programs

  • PARI
    print1(1,", ");n=2;while(n<20,m=1;for(k=1,n,while(m,d=digits(m^k,n);if(#vecsort(d,,8)!=k,m++);if(#vecsort(d,,8)==k,print1(m,", ");m=1;break)));n++)

A247047 Numbers k such that k^2 contains exactly 2 distinct digits and k^3 contains exactly 3 distinct digits.

Original entry on oeis.org

5, 6, 8, 9, 15, 30, 173, 300, 3000, 30000, 300000, 3000000, 30000000, 300000000, 3000000000, 30000000000, 300000000000, 3000000000000, 30000000000000, 300000000000000, 3000000000000000
Offset: 1

Views

Author

Derek Orr, Sep 10 2014

Keywords

Comments

Intersection of A016069 and A155146.
This sequence is infinite since 3*10^k is always in this sequence for k > 0.
Is 173 the last term not of the form 3*10^k?
3*10^7 < a(14) <= 3*10^8.
The numbers k such that k^2 contains 2 distinct digits, k^3 contains 3 distinct digits, and k^4 contains 4 distinct digits are conjectured to only be 6, 8, and 15. (Intersection of A016069, A155146, and A155150.)

Examples

			k = 15 is a member of this sequence since 15^2 = 225 contains two distinct digits and 15^3 = 3375 contains three distinct digits.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[3*10^6],Length[DeleteCases[DigitCount[#^2],0]]==2&&Length[ DeleteCases[ DigitCount[#^3],0]]==3&] (* The program generates the first 12 terms of the sequence. *) (* Harvey P. Dale, Jan 21 2023 *)
  • PARI
    for(n=1,3*10^7,d2=digits(n^2);d3=digits(n^3);if(#vecsort(d2,,8)==2&&#vecsort(d3,,8)==3,print1(n,", ")))
    
  • Python
    A247047_list = [n for n in range(1,10**6) if len(set(str(n**3))) == 3 and len(set(str(n**2))) == 2]
    # Chai Wah Wu, Sep 26 2014

Extensions

a(14)-a(15) from Chai Wah Wu, Sep 26 2014
a(16)-a(18) from Kevin P. Thompson, Jul 01 2022
a(19)-a(21) from Michael S. Branicky, Jun 05 2025

A385175 Cubes using at most three distinct digits, not ending in 0.

Original entry on oeis.org

1, 8, 27, 64, 125, 216, 343, 512, 729, 1331, 2744, 3375, 46656, 238328, 778688, 1030301, 5177717, 7077888, 9393931, 700227072, 1003003001, 44474744007, 1000300030001, 1000030000300001, 1331399339931331, 3163316636166336, 1000003000003000001, 1000000300000030000001, 1000000030000000300000001
Offset: 1

Views

Author

Gonzalo Martínez, Jun 20 2025

Keywords

Comments

This sequence has infinitely many terms since (10^m + 1)^3 is a term for all m >= 0.
Conjecture: a(26) = 3163316636166336 is the largest term with nonzero digits (See comments of A030294 and the data of A155146, where a(26) = A155146(47)^3).

Examples

			8, 343, and 46656 belong to this list because they are cubes that use 1, 2, and 3 distinct digits, respectively.
		

Crossrefs

Programs

  • Mathematica
    Select[Range[10^6]^3,Length[Union[IntegerDigits[#]]]<4&&IntegerDigits[#][[-1]]!=0&] (* James C. McMahon, Jun 30 2025 *)
    fQ[n_] := Mod[n, 10] > 0 && Length@ Union@ IntegerDigits[n^3] < 4; k = 1; lst = {}; While[k < 1000002, If[ fQ@k, AppendTo[lst, k]]; k++]; lst^3 (* Robert G. Wilson v, Jul 10 2025 *)

Formula

a(n) = A202940(n)^3.

Extensions

a(28) from Robert G. Wilson v, Jul 10 2025
a(29) from David A. Corneth, Jul 10 2025
Showing 1-9 of 9 results.