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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A243539 Numbers n such that the list of divisors of n contains 6 distinct digits (in base 10).

Original entry on oeis.org

18, 24, 30, 32, 40, 42, 48, 52, 63, 64, 81, 86, 87, 92, 98, 105, 106, 128, 130, 134, 146, 147, 148, 158, 176, 186, 188, 198, 200, 201, 203, 222, 235, 246, 247, 248, 249, 255, 259, 264, 278, 286, 310, 314, 322, 327, 328, 329, 330, 332, 334, 338, 346, 351, 357
Offset: 1

Views

Author

Jaroslav Krizek, Jun 19 2014

Keywords

Comments

Numbers n such that A037278(n), A176558(n) and A243360(n) contain 6 distinct digits.

Examples

			48 is in sequence because the list of divisors of 48: (1, 2, 3, 4, 6, 8, 12, 16, 24, 48) contains 6 distinct digits (1, 2, 3, 4, 6, 8).
		

Crossrefs

Sequences of numbers n such that the list of divisors of n contains k distinct digits for 1 <= k <= 10: k = 1: A243534; k = 2: A243535; k = 3: A243536; k = 4: A243537; k = 5: A243538; k = 6: A243539; k = 7: A243540; k = 8: A243541; k = 9: A243542; k = 10: A095050.
Cf. A243543 (the smallest number m whose list of divisors contains n distinct digits).

Programs

  • Excel
    [Row n = 1...10000; Column A: A(n) = A095048(n); Column B: B(n) = IF(A(n)=6;A(n)); Arrangement of column B]
  • Mathematica
    Select[Range[400],Length[Union[Flatten[IntegerDigits/@Divisors[#]]]]==6&] (* Harvey P. Dale, Apr 13 2025 *)

A243540 Numbers n such that the list of divisors of n contains 7 distinct digits (in base 10).

Original entry on oeis.org

36, 56, 60, 68, 70, 78, 80, 84, 96, 112, 116, 135, 136, 138, 150, 172, 184, 189, 190, 192, 196, 207, 212, 225, 230, 238, 243, 245, 256, 260, 261, 267, 268, 272, 285, 290, 292, 344, 345, 350, 358, 368, 384, 387, 388, 396, 400, 402, 418, 441, 444, 455, 459, 462
Offset: 1

Views

Author

Jaroslav Krizek, Jun 19 2014

Keywords

Comments

Numbers n such that A037278(n), A176558(n) and A243360(n) contain 7 distinct digits.

Examples

			36 is in sequence because the list of divisors of 36: (1, 2, 3, 4, 6, 9, 12, 18, 36) contains 7 distinct digits (1, 2, 3, 4, 6, 8, 9).
		

Crossrefs

Sequences of numbers n such that the list of divisors of n contains k distinct digits for 1 <= k <= 10: k = 1: A243534; k = 2: A243535; k = 3: A243536; k = 4: A243537; k = 5: A243538; k = 6: A243539; k = 7: A243540; k = 8: A243541; k = 9: A243542; k = 10: A095050.
Cf. A243543 (the smallest number m whose list of divisors contains n distinct digits).

Programs

  • Excel
    [Row n = 1...10000; Column A: A(n) = A095048(n); Column B: B(n) = IF(A(n)=7;A(n)); Arrangement of column B]

A243541 Numbers n such that the list of divisors of n contains 8 distinct digits (in base 10).

Original entry on oeis.org

72, 76, 102, 104, 120, 126, 140, 144, 160, 168, 170, 182, 208, 210, 224, 232, 234, 236, 240, 258, 266, 276, 282, 288, 294, 296, 300, 308, 318, 320, 336, 352, 370, 372, 376, 416, 424, 430, 435, 436, 438, 448, 460, 464, 470, 476, 483, 494, 518, 520, 528, 536
Offset: 1

Views

Author

Jaroslav Krizek, Jun 19 2014

Keywords

Comments

Numbers n such that A037278(n), A176558(n) and A243360(n) contain 8 distinct digits.

Examples

			72 is in sequence because the list of divisors of 72: (1, 2, 3, 4, 6, 8, 9, 12, 18, 24, 36, 72) contains 8 distinct digits (1, 2, 3, 4, 6, 7, 8, 9).
		

Crossrefs

Sequences of numbers n such that the list of divisors of n contains k distinct digits for 1 <= k <= 10: k = 1: A243534; k = 2: A243535; k = 3: A243536; k = 4: A243537; k = 5: A243538; k = 6: A243539; k = 7: A243540; k = 8: A243541; k = 9: A243542; k = 10: A095050.
Cf. A243543 (the smallest number m whose list of divisors contains n distinct digits).

Programs

  • Excel
    [Row n = 1 …10000; Column A: A(n) = A095048(n); Column B: B(n) = IF(A(n)=8;A(n)); Arrangement of column B]
  • Mathematica
    Select[Range[600],Length[Union[Flatten[IntegerDigits/@Divisors[#]]]]==8&] (* Harvey P. Dale, Jul 14 2016 *)

A243542 Numbers n such that the list of divisors of n contains 9 distinct digits (in base 10).

Original entry on oeis.org

54, 90, 114, 152, 156, 162, 174, 180, 204, 228, 252, 280, 315, 316, 340, 342, 348, 354, 356, 364, 378, 390, 392, 405, 408, 414, 420, 456, 468, 472, 474, 480, 486, 490, 510, 516, 522, 532, 534, 546, 552, 556, 560, 564, 576, 582, 584, 588, 592, 594, 600, 616
Offset: 1

Views

Author

Jaroslav Krizek, Jun 19 2014

Keywords

Comments

Numbers n such that A037278(n), A176558(n) and A243360(n) contain 9 distinct digits.

Examples

			54 is in sequence because the list of divisors of 54: (1, 2, 3, 6, 9, 18, 27, 54) contains 9 distinct digits (1, 2, 3, 4, 5, 6, 7, 8, 9).
		

Crossrefs

Sequences of numbers n such that the list of divisors of n contains k distinct digits for 1 <= k <= 10: k = 1: A243534; k = 2: A243535; k = 3: A243536; k = 4: A243537; k = 5: A243538; k = 6: A243539; k = 7: A243540; k = 8: A243541; k = 9: A243542; k = 10: A095050.
Cf. A243543 (the smallest number m whose list of divisors contains n distinct digits).

Programs

  • Excel
    [Row n = 1 …10000; Column A: A(n) = A095048(n); Column B: B(n) = IF(A(n)=9;A(n)); Arrangement of column B]

A243543 Smallest number whose list of divisors contains n distinct digits (in base 10).

Original entry on oeis.org

1, 2, 4, 6, 12, 18, 36, 72, 54, 108
Offset: 1

Views

Author

Jaroslav Krizek, Jun 19 2014

Keywords

Comments

Finite sequence with 10 terms.

Examples

			a(9) = 54 because 54 is the smallest number whose list of divisors contains 9 distinct digits; the list of divisors of 54: (1, 2, 3, 6, 9, 18, 27, 54) contains 9 distinct digits (1, 2, 3, 4, 5, 6, 7, 8, 9).
		

Crossrefs

Cf. Sequences of numbers n such that list of divisors of n contains k distinct digits: k = 1: A243534; k = 2: A243535; k = 3: A243536; k = 4: A243537; k = 5: A243538; k = 6: A243539; k = 7: A243540; k = 8: A243541; k = 9: A243542; k = 10: A095050.

A209932 Numbers n such that smallest digit of all divisors of n is 0.

Original entry on oeis.org

10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 212, 214, 216, 218, 220, 230, 240, 250, 260, 270, 280, 290, 300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 312, 315, 318, 320, 321, 324, 327, 330, 340, 350, 360, 370, 380, 390, 400
Offset: 1

Views

Author

Jaroslav Krizek, Mar 20 2012

Keywords

Comments

Also numbers n such that smallest digit of concatenation of all divisors of n (A037278 or A176558) is 0.
Sequence is not the same as A011540, first deviation is at a(41): A011540(41) = 220, a(41) = 214.

Examples

			Number 214 is in sequence because smallest digit of all divisors of 214 (1, 2, 107, 214) is 0.
		

Crossrefs

Cf. A209929 (smallest digit of all divisors of n), complement of A209931.

Programs

  • Mathematica
    Select[Range[400],Min[Flatten[IntegerDigits/@Divisors[#]]]==0&] (* Harvey P. Dale, Dec 03 2021 *)

Extensions

Corrected and extended by Harvey P. Dale, Dec 03 2021

A257219 Numbers that have at least one divisor containing the digit 2 in base 10.

Original entry on oeis.org

2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 63, 64, 66, 68, 69, 70, 72, 74, 75, 76, 78, 80, 81, 82, 84, 86, 87, 88, 90, 92, 94, 96, 98, 100, 102, 104, 105, 106, 108
Offset: 1

Views

Author

Jaroslav Krizek, Apr 20 2015

Keywords

Comments

Numbers k whose concatenation of divisors A037278(k), A176558(k), A243360(k) or A256824(k) contains a digit 2.
Sequences of numbers k whose concatenation of divisors contains a digit j in base 10 for 0 <= j <= 9: A209932 for j = 0, A000027 for j = 1, A257219 for j = 2, A257220 for j = 3, A257221 for j = 4, A257222 for j = 5, A257223 for j = 6, A257224 for j = 7, A257225 for j = 8, A257226 for j = 9.
All even numbers and all numbers which have a digit "2" themselves are trivially in this sequence. The first terms not of this form are the odd multiples of odd numbers between 21 and 29: { 63 = 3*21, 69 = 3*23, 75 = 3*25, 81 = 3*27, 87 = 3*29, 105 = 5*21, 115 = 5*23, 135 = 5*27, 145 = 5*29, ...}. - M. F. Hasler, Apr 22 2015
A011532 (numbers that contain a 2) is a subsequence. - Michel Marcus, May 19 2015

Examples

			18 is in sequence because the list of divisors of 18: (1, 2, 3, 6, 9, 18) contains digit 2.
In the same way all even numbers have the divisor 2 and thus are in this sequence; numbers N in { 20,...,29, 120,...,129, 200,...,299 } have the digit 2 in N which is divisor of itself. - _M. F. Hasler_, Apr 22 2015
		

Crossrefs

Programs

  • Magma
    [n: n in [1..1000] | [2] subset Setseq(Set(Sort(&cat[Intseq(d): d in Divisors(n)])))]
    
  • Mathematica
    Select[Range@108, Part[Plus @@ DigitCount@ Divisors@ #, 2] > 0 &] (* Michael De Vlieger, Apr 20 2015 *)
  • PARI
    is(n)=!bittest(n,0)||setsearch(Set(digits(n)),2)||fordiv(n,d,setsearch(Set(digits(d)),2)&&return(1)) \\ M. F. Hasler, Apr 22 2015

Formula

a(n) ~ n. - Charles R Greathouse IV, Apr 22 2015

A257220 Numbers that have at least one divisor containing the digit 3 in base 10.

Original entry on oeis.org

3, 6, 9, 12, 13, 15, 18, 21, 23, 24, 26, 27, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 42, 43, 45, 46, 48, 51, 52, 53, 54, 57, 60, 62, 63, 64, 65, 66, 68, 69, 70, 72, 73, 74, 75, 76, 78, 81, 83, 84, 86, 87, 90, 91, 92, 93, 96, 99, 102, 103, 104, 105, 106, 108
Offset: 1

Views

Author

Jaroslav Krizek, Apr 20 2015

Keywords

Comments

Numbers k whose concatenation of divisors A037278(k), A176558(k), A243360(k) or A256824(k) contains a digit 3.
Sequences of numbers k whose concatenation of divisors contains a digit j in base 10 for 0 <= j <= 9: A209932 for j = 0, A000027 for j = 1, A257219 for j = 2, A257220 for j = 3, A257221 for j = 4, A257222 for j = 5, A257223 for j = 6, A257224 for j = 7, A257225 for j = 8, A257226 for j = 9.

Examples

			18 is in sequence because the list of divisors of 18: (1, 2, 3, 6, 9, 18) contains digit 3.
		

Crossrefs

Programs

  • Magma
    [n: n in [1..1000] | [3] subset Setseq(Set(Sort(&cat[Intseq(d): d in Divisors(n)])))];
    
  • Mathematica
    Select[Range@108, Part[Plus @@ DigitCount@ Divisors@ #, 3] > 0 &] (* Michael De Vlieger, Apr 20 2015 *)
  • PARI
    is(n)=fordiv(n,d, if(setsearch(Set(digits(d)),3), return(1))); 0 \\ Charles R Greathouse IV, Apr 30 2015

Formula

a(n) ~ n. - Charles R Greathouse IV, Apr 30 2015

A257221 Numbers that have at least one divisor containing the digit 4 in base 10.

Original entry on oeis.org

4, 8, 12, 14, 16, 20, 24, 28, 32, 34, 36, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 52, 54, 56, 60, 64, 68, 70, 72, 74, 76, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 108, 112, 114, 116, 120, 123, 124, 126, 128, 129, 132, 134, 135, 136, 138, 140, 141
Offset: 1

Views

Author

Jaroslav Krizek, Apr 20 2015

Keywords

Comments

Numbers k whose concatenation of divisors A037278(k), A176558(k), A243360(k) or A256824(k) contains a digit 4.
Sequences of numbers k whose concatenation of divisors contains a digit j in base 10 for 0 <= j <= 9: A209932 for j = 0, A000027 for j = 1, A257219 for j = 2, A257220 for j = 3, A257221 for j = 4, A257222 for j = 5, A257223 for j = 6, A257224 for j = 7, A257225 for j = 8, A257226 for j = 9.

Examples

			16 is in sequence because the list of divisors of 16: (1, 2, 4, 8, 16) contains digit 4.
		

Crossrefs

Programs

  • Magma
    [n: n in [1..1000] | [4] subset Setseq(Set(Sort(&cat[Intseq(d): d in Divisors(n)])))]
    
  • Mathematica
    Select[Range@ 141, Part[Plus @@ DigitCount@ Divisors@ #, 4] > 0 &] (* Michael De Vlieger, Apr 20 2015 *)
    Select[Range[200],Count[Flatten[IntegerDigits/@Divisors[#]],4]>0&] (* Harvey P. Dale, May 05 2022 *)
  • PARI
    is(n)=fordiv(n,d, if(setsearch(Set(digits(d)),4), return(1))); 0 \\ Charles R Greathouse IV, Apr 30 2015

Formula

a(n) ~ n. - Charles R Greathouse IV, Apr 30 2015

A257222 Numbers that have at least one divisor containing the digit 5 in base 10.

Original entry on oeis.org

5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 65, 70, 75, 80, 85, 90, 95, 100, 102, 104, 105, 106, 108, 110, 112, 114, 115, 116, 118, 120, 125, 130, 135, 140, 145, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 162, 165
Offset: 1

Views

Author

Jaroslav Krizek, May 05 2015

Keywords

Comments

Numbers k whose concatenation of divisors A037278(k), A176558(k), A243360(k) or A256824(k) contains a digit 5.
Sequences of numbers k whose concatenation of divisors contains a digit j in base 10 for 0 <= j <= 9: A209932 for j = 0, A000027 for j = 1, A257219 for j = 2, A257220 for j = 3, A257221 for j = 4, A257222 for j = 5, A257223 for j = 6, A257224 for j = 7, A257225 for j = 8, A257226 for j = 9.

Examples

			20 is in sequence because the list of divisors of 20: (1, 2, 4, 5, 10, 20) contains digit 5.
		

Crossrefs

Programs

  • Magma
    [n: n in [1..1000] | [5] subset Setseq(Set(Sort(&cat[Intseq(d): d in Divisors(n)])))];
    
  • Mathematica
    Select[Range@108, Part[Plus @@ DigitCount@ Divisors@ #, 5] > 0 &]
    Select[Range[200],Max[DigitCount[Divisors[#],10,5]]>0&] (* Harvey P. Dale, Sep 15 2018 *)
  • PARI
    is(n)=fordiv(n, d, if(setsearch(Set(digits(d)), 5), return(1))); 0
    
  • Perl
    use ntheory ":all"; for my $n (1..1000) { say $n if scalar(grep {/5/} divisors($n)) } # Dana Jacobsen, May 07 2015
    
  • Perl
    use ntheory ":all"; my @a257222 = grep { scalar(grep {/5/} divisors($)) } 1..1000; # _Dana Jacobsen, May 07 2015
  • Python
    from sympy import divisors
    A257222_list = [n for n in range(1,10**3) if '5' in set().union(*(set(str(d)) for d in divisors(n,generator=True)))] # Chai Wah Wu, May 06 2015
    

Formula

a(n) ~ n.

Extensions

Mathematica and PARI programs with assistance from Michael De Vlieger and Charles R Greathouse IV, respectively.
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