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.

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A238939 Powers of 3 without the digit '0' in their decimal expansion.

Original entry on oeis.org

1, 3, 9, 27, 81, 243, 729, 2187, 6561, 19683, 177147, 531441, 1594323, 4782969, 1162261467, 94143178827, 282429536481, 2541865828329, 7625597484987, 22876792454961, 617673396283947, 16677181699666569, 278128389443693511257285776231761
Offset: 1

Views

Author

M. F. Hasler, Mar 07 2014

Keywords

Comments

Conjectured to be finite and complete. See the OEIS wiki page for further information, references and links.

Crossrefs

For the zeroless numbers (powers x^n), see A238938, A238939, A238940, A195948, A238936, A195908, A195946, A195945, A195942, A195943, A103662.
For the corresponding exponents, see A007377, A008839, A030700, A030701, A008839, A030702, A030703, A030704, A030705, A030706, A195944.
For other related sequences, see A052382, A027870, A102483, A103663.

Programs

  • Mathematica
    Select[3^Range[0,100],DigitCount[#,10,0]==0&] (* Paolo Xausa, Oct 07 2023 *)
  • PARI
    for(n=0,99,vecmin(digits(3^n))&& print1(3^n","))

Formula

a(n) = 3^A030700(n).

Extensions

Keyword:fini removed by Jianing Song, Jan 28 2023 as finiteness is only conjectured.

A065712 Number of 1's in decimal expansion of 2^n.

Original entry on oeis.org

1, 0, 0, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 2, 1, 0, 1, 1, 1, 0, 2, 0, 1, 2, 0, 1, 2, 1, 0, 0, 3, 0, 1, 1, 0, 1, 3, 1, 3, 0, 3, 1, 1, 1, 2, 2, 2, 2, 0, 1, 3, 1, 0, 4, 4, 0, 3, 1, 3, 0, 3, 3, 0, 2, 2, 3, 6, 3, 1, 0, 2, 3, 3, 5, 1, 1, 5, 3, 1, 2, 5, 1, 4, 2, 2, 5, 2, 0, 5, 3, 1, 6, 2, 2, 4, 5, 2
Offset: 0

Views

Author

Benoit Cloitre, Dec 04 2001

Keywords

Comments

I conjecture that any value x = 0, 1, 2, ... occurs only a finite number of times N(x) = 26, 34, 30, 40, 26, 33, 39, 30, 30, 30, 38, ... in this sequence, for the last time at well defined indices i(x) = 91, 152, 185, 412, 245, 505, 346, 422, 499, 565, 529, 575, ... - M. F. Hasler, Jul 09 2025

Examples

			2^17 = 131072 so a(17) = 2.
		

Crossrefs

Cf. A027870 (0's), A065710 (2's), A065714 (3's), A065715 (4's), A065716 (5's), A065717 (6's), A065718 (7's), A065719 (8's), A065744 (9's).
Indices of zeros are listed in A035057 (2^n does not contain the digit 1).

Programs

  • Mathematica
    Table[ Count[ IntegerDigits[2^n], 1], {n, 0, 100} ]
    Table[DigitCount[2^n,10,1],{n,0,120}] (* Harvey P. Dale, Aug 15 2014 *)
  • PARI
    a(n) = #select(x->(x==1), digits(2^n)); \\ Michel Marcus, Jun 15 2018
    
  • Python
    def A065712(n):
        return str(2**n).count('1') # Chai Wah Wu, Feb 14 2020

Extensions

More terms from Robert G. Wilson v, Dec 07 2001

A238936 Powers of 6 without the digit '0' in their decimal expansion.

Original entry on oeis.org

1, 6, 36, 216, 1296, 7776, 46656, 279936, 1679616, 2176782336, 16926659444736, 4738381338321616896, 36845653286788892983296, 17324272922341479351919144385642496
Offset: 1

Views

Author

M. F. Hasler, Mar 07 2014

Keywords

Comments

Conjectured to be finite and complete. See the OEIS wiki page for further information, references and links.

Crossrefs

Programs

  • Mathematica
    Select[6^Range[0,50],DigitCount[#,10,0]==0&] (* Harvey P. Dale, Dec 03 2020 *)
  • PARI
    for(n=0,99,vecmin(digits(6^n))&& print1(6^n","))

Formula

a(n)=6^A030702(n).

Extensions

Keyword:fini and keyword:full removed by Jianing Song, Jan 28 2023 as finiteness is only conjectured.

A238940 Powers of 4 without the digit '0' in their decimal expansion.

Original entry on oeis.org

1, 4, 16, 64, 256, 16384, 65536, 262144, 16777216, 268435456, 4294967296, 17179869184, 68719476736, 4722366482869645213696, 75557863725914323419136, 77371252455336267181195264
Offset: 1

Views

Author

M. F. Hasler, Mar 07 2014

Keywords

Comments

Conjectured to be finite and complete. See the OEIS wiki page for further information, references and links.

Crossrefs

For the zeroless numbers (powers x^n), see A238938, A238939, A238940, A195948, A238936, A195908, A195946, A195945, A195942, A195943.
For the corresponding exponents, see A007377, A008839, A030700, A030701, A030702, A030703, A030704, A030705, A030706, A195944.
For other related sequences, see A052382, A027870, A102483.

Programs

  • Mathematica
    Select[4^Range[0,50],DigitCount[#,10,0]==0&] (* Harvey P. Dale, Aug 31 2021 *)
  • PARI
    for(n=0,99,vecmin(digits(4^n))&& print1(4^n","))

Formula

a(n)=4^A030701(n).

Extensions

Keyword:fini removed by Jianing Song, Jan 28 2023 as finiteness is only conjectured.

A065715 Number of 4's in decimal expansion of 2^n.

Original entry on oeis.org

0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 1, 1, 0, 1, 0, 0, 0, 2, 1, 1, 0, 3, 0, 0, 2, 1, 1, 2, 0, 2, 3, 2, 1, 1, 1, 1, 2, 3, 1, 0, 0, 3, 0, 3, 1, 3, 2, 2, 2, 2, 1, 2, 2, 3, 0, 1, 2, 2, 3, 2, 1, 3, 1, 4, 3, 3, 2, 1, 0, 3, 4, 3, 4, 4, 0, 2, 2, 4, 3, 2, 3, 4, 3, 2, 0, 2, 4, 3, 3, 4, 5, 3, 2, 3, 1, 3, 1, 3, 3, 2
Offset: 0

Views

Author

Benoit Cloitre, Dec 04 2001

Keywords

Comments

2^10 = 1024 so a(10)=1.

Crossrefs

Cf. 0's A027870, 1's A065712, 2's A065710, 3's A065714, 5's A065716, 6's A065717, 7's A065718, 8's A065719, 9's A065744.

Programs

  • Mathematica
    Table[ Count[ IntegerDigits[2^n], 4], {n, 0, 100} ]
  • PARI
    a(n) = #select(x->(x==4), digits(2^n)); \\ Michel Marcus, Jun 15 2018
    
  • Python
    def A065715(n):
        return str(2**n).count('4') # Chai Wah Wu, Feb 14 2020

Extensions

More terms from Robert G. Wilson v, Dec 07 2001

A065719 Number of 8's in decimal expansion of 2^n.

Original entry on oeis.org

0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 2, 1, 0, 0, 4, 0, 0, 2, 1, 1, 1, 1, 2, 0, 2, 2, 2, 1, 1, 1, 4, 0, 0, 1, 2, 1, 4, 1, 3, 1, 0, 2, 3, 0, 0, 4, 3, 0, 4, 2, 2, 1, 1, 3, 3, 1, 3, 3, 2, 2, 2, 1, 4, 2, 0, 7, 3, 1, 4, 0, 4, 2, 2, 5, 1, 4, 3, 1, 1, 4, 1, 3, 6, 1, 1, 7, 3, 1, 5, 1, 4, 1
Offset: 0

Views

Author

Benoit Cloitre, Dec 04 2001

Keywords

Comments

2^7 = 128 so a(7)=1.

Crossrefs

Cf. 0's A027870, 1's A065712, 2's A065710, 3's A065714, 4's A065715, 5's A065716, 6's A065717, 7's A065718, 9's A065744.

Programs

  • Mathematica
    Table[ Count[ IntegerDigits[2^n], 8], {n, 0, 100} ]
    DigitCount[2^Range[0,100],10,8] (* Harvey P. Dale, Aug 02 2024 *)
  • PARI
    a(n) = #select(x->(x==8), digits(2^n)); \\ Michel Marcus, Jun 15 2018
    
  • Python
    def A065719(n):
        return str(2**n).count('8') # Chai Wah Wu, Feb 14 2020

Extensions

More terms from Robert G. Wilson v, Dec 07 2001

A065744 Number of 9's in the decimal expansion of 2^n.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 3, 3, 2, 1, 1, 1, 2, 1, 2, 2, 1, 2, 1, 0, 0, 0, 1, 3, 3, 2, 3, 5, 3, 3, 3, 0, 0, 0, 2, 3, 1, 1, 1, 2, 2, 3, 3, 2, 1, 0, 2, 5, 2, 3, 2, 0, 2, 2, 3, 3, 1, 4, 3, 2, 1, 2, 2, 4, 4, 2, 6, 8, 3, 3, 3, 1, 1, 0, 2
Offset: 0

Views

Author

Benoit Cloitre, Dec 04 2001

Keywords

Comments

See A035064 for the indices of zeros. I conjecture that any value x = 0, 1, 2, ... occurs only a finite number of times N(x) = 37, 27, 36, 46, 20, 31, 32, 30, 46, 29, 22, ... in this sequence, for the last time at well defined indices i(x) = 108, 197, 296, 277, 278, 315, 379, 555, 503, 504, 539, 696, 667, ... - M. F. Hasler, Jul 09 2025

Examples

			2^12 = 4096 so a(12)=1.
		

Crossrefs

Similar for other digits: A027870 (0's), A065712 (1's), A065710 (2's), A065714 (3's), A065715 (4's), A065716 (5's), A065717 (6's), A065718 (7's), A065719 (8's).
Cf. A035064 (2^n has no digit 9).

Programs

  • Mathematica
    Table[ Count[ IntegerDigits[2^n], 9], {n, 0, 100} ]
  • PARI
    Count(x,d)={ #select(t->t==d, digits(x)) }
    a(n) = Count(2^n, 9) \\ Harry J. Smith, Oct 27 2009
    
  • Python
    def A065744(n):
        return str(2**n).count('9')  # Chai Wah Wu, Feb 14 2020

Extensions

More terms from Robert G. Wilson v, Dec 07 2001

A065714 Number of 3's in decimal expansion of 2^n.

Original entry on oeis.org

0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 3, 0, 1, 1, 1, 1, 1, 0, 1, 0, 4, 1, 3, 0, 1, 0, 1, 1, 1, 0, 3, 1, 3, 0, 2, 0, 1, 2, 0, 1, 2, 2, 0, 2, 3, 0, 4, 1, 3, 1, 4, 2, 1, 1, 1, 2, 3, 2, 3, 1, 2, 4, 1, 4, 3, 0, 3, 2, 3, 4, 4, 3, 3, 2, 1, 3, 0, 0, 4, 2, 2, 6, 1, 4, 4, 2
Offset: 0

Views

Author

Benoit Cloitre, Dec 04 2001

Keywords

Comments

I conjecture that any value x = 0, 1, 2, ... occurs only a finite number of times N(x) = 34, 34, 24, 34, 39, 34, 35, 34, 35, 32, 33, 31, ... in this sequence, for the last time at well defined indices i(x) = 153, 139, 226, 237, 308, 386, 413, 506, 461, 578, 644, 732, 857, 657, 743, 768, 784, 848, 906, ... - M. F. Hasler, Jul 09 2025

Examples

			2^5 = 32 so a(5)=1.
		

Crossrefs

Cf. A000079 (powers of 2), A035058 (2^n does not contain the digit 3).
Similar for other digits: A027870 (0's), A065712 (1's), A065710 (2's), this (3's), A065715 (4's), A065716 (5's), A065717 (6's), A065718 (7's), A065719 (8's), A065744 (9's).
Cf. A094776 (index of last occurrence of digit n in powers of 2).

Programs

  • Mathematica
    Table[ Count[ IntegerDigits[2^n], 3], {n, 0, 100} ]
  • PARI
    a(n) = #select(x->(x==3), digits(2^n)); \\ Michel Marcus, Jun 15 2018
    
  • Python
    def A065714(n):
        return str(2**n).count('3') # Chai Wah Wu, Feb 14 2020

Extensions

More terms from Robert G. Wilson v, Dec 07 2001

A065716 Number of 5's in decimal expansion of 2^n.

Original entry on oeis.org

0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 2, 0, 0, 1, 1, 1, 0, 0, 0, 2, 0, 0, 2, 1, 0, 0, 0, 2, 0, 1, 0, 1, 0, 3, 1, 4, 1, 0, 1, 1, 0, 2, 1, 2, 1, 2, 2, 1, 1, 0, 2, 4, 1, 2, 2, 2, 0, 2, 2, 0, 0, 3, 5, 5, 1, 0, 1, 1, 3, 2, 4, 3, 3, 2, 1, 3, 3, 2, 1, 3, 4, 4, 3, 1, 1, 3, 4, 1, 3, 2, 4, 5, 5, 2, 2
Offset: 0

Views

Author

Benoit Cloitre, Dec 04 2001

Keywords

Examples

			2^8 = 256 so a(8)=1.
		

Crossrefs

Cf. 0's A027870, 1's A065712, 2's A065710, 3's A065714, 4's A065715, 6's A065717, 7's A065718, 8's A065719, 9's A065744.

Programs

  • Mathematica
    Table[ Count[ IntegerDigits[2^n], 5], {n, 0, 100} ]
    DigitCount[#,10,5]&/@(2^Range[0,100]) (* Harvey P. Dale, Nov 13 2021 *)
  • PARI
    a(n) = #select(x->(x==5), digits(2^n)); \\ Michel Marcus, Jun 15 2018
    
  • Python
    def A065716(n):
        return str(2**n).count('5') # Chai Wah Wu, Feb 14 2020

Extensions

More terms from Robert G. Wilson v, Dec 07 2001

A065717 Number of 6's in decimal expansion of 2^n.

Original entry on oeis.org

0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 1, 2, 0, 1, 0, 1, 0, 0, 1, 2, 0, 2, 0, 2, 1, 0, 1, 2, 0, 1, 1, 3, 0, 1, 0, 2, 0, 1, 1, 2, 0, 3, 0, 3, 1, 2, 1, 2, 0, 0, 3, 1, 0, 1, 2, 4, 1, 3, 1, 3, 1, 4, 2, 1, 1, 1, 3, 6, 1, 1, 3, 2, 2, 3, 2, 4, 1, 2, 4, 3, 6, 3, 2, 2, 4, 0, 1, 4, 0, 3, 4, 3, 3, 2, 3, 5
Offset: 0

Views

Author

Benoit Cloitre, Dec 04 2001

Keywords

Examples

			2^8 = 256 so a(8)=1.
		

Crossrefs

Cf. 0's A027870, 1's A065712, 2's A065710, 3's A065714, 4's A065715, 5's A065716, 7's A065718, 8's A065719, 9's A065744.

Programs

  • Mathematica
    Table[ Count[ IntegerDigits[2^n], 6], {n, 0, 100} ]
    DigitCount[#,10,6]&/@(2^Range[0,100]) (* Harvey P. Dale, Feb 15 2020 *)
  • PARI
    a(n) = #select(x->(x==6), digits(2^n)); \\ Andrew Howroyd, Apr 25 2020
    
  • Python
    def A065717(n):
        return str(2**n).count('6') # Chai Wah Wu, Feb 14 2020

Extensions

More terms from Robert G. Wilson v, Dec 07 2001
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