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 1-6 of 6 results.

A029793 Numbers k such that k and k^2 have the same set of digits.

Original entry on oeis.org

0, 1, 10, 100, 1000, 4762, 4832, 10000, 10376, 10493, 11205, 12385, 12650, 14829, 22450, 23506, 24605, 26394, 34196, 36215, 47620, 48302, 48320, 49827, 64510, 68474, 71205, 72510, 72576, 74510, 74528, 79286, 79603, 79836, 94583, 94867, 96123, 98376
Offset: 1

Views

Author

Keywords

Comments

This sequence has density 1: almost all numbers k have all 10 digits in both k and k^2. - Franklin T. Adams-Watters, Jun 28 2011

Examples

			{0, 1, 3, 4, 9} = digits of a(10) = 10493 and of 10493^2 = 110103049;
{0, 1, 2, 5, 6} = digits of a(100) = 162025 and of 162025^2 = 26252100625;
{0, 1, 3, 4, 6, 7, 8} = digits of a(1000) = 1764380 and of 1764380^2 = 3113036784400;
{1, 2, 3, 4, 7, 8, 9} = digits of a(10000) = 14872239 and of 14872239^2 = 221183492873121.
		

Crossrefs

Programs

  • Haskell
    import Data.List (nub, sort)
    a029793 n = a029793_list !! (n-1)
    a029793_list = filter (\x -> digs x == digs (x^2)) [0..]
       where digs = sort . nub . show
    -- Reinhard Zumkeller, Jun 27 2011
    
  • Magma
    [ n: n in [0..10^5] | Set(Intseq(n)) eq Set(Intseq(n^2)) ];  // Bruno Berselli, Jun 28 2011
    
  • Maple
    seq(`if`(convert(convert(n,base,10),set) = convert(convert(n^2,base,10),set), n, NULL), n=0..100000); # Nathaniel Johnston, Jun 28 2011
  • Mathematica
    digitSet[n_] := Union[IntegerDigits[n]]; Select[Range[0, 99000], digitSet[#] == digitSet[#^2] &] (* Jayanta Basu, Jun 02 2013 *)
  • PARI
    isA029793(n)=Set(Vec(Str(n)))==Set(Vec(Str(n^2))) \\ Charles R Greathouse IV, Jun 28 2011
    
  • Scala
    (0L to 99999L).filter(n => n.toString.toCharArray.toSet == (n * n).toString.toCharArray.toSet) // Alonso del Arte, Jan 19 2020

A029795 Numbers k such that k and k^3 have the same set of digits.

Original entry on oeis.org

0, 1, 10, 100, 1000, 10000, 100000, 107624, 109573, 132485, 138624, 159406, 165640, 192574, 205738, 215806, 251894, 281536, 318725, 419375, 427863, 568314, 642510, 713960, 953867, 954086, 963218, 965760, 1000000, 1008529, 1023479
Offset: 1

Views

Author

Keywords

Comments

Conjecture: there exists some m and N for which a(n) = m + n for all n >= N. - Charles R Greathouse IV, Jun 28 2011

Examples

			109573^3 = 1315559990715517. Since both numbers use the digits 0, 1, 3, 5, 7, 9, and no others, 109573 is in the sequence.
		

Crossrefs

Programs

  • Magma
    [ n: n in [0..8*10^6] | Set(Intseq(n)) eq Set(Intseq(n^3)) ];  // Bruno Berselli, Jun 28 2011
    
  • Maple
    seq(`if`(convert(convert(n, base, 10), set) = convert(convert(n^3, base, 10), set), n, NULL), n=0..500000); # Nathaniel Johnston, Jun 28 2011
  • Mathematica
    Select[Range[0, 199999], Union[IntegerDigits[#]] == Union[IntegerDigits[#^3]] &] (* Alonso del Arte, Jan 12 2020 *)
  • PARI
    isA029795(n)=Set(Vec(Str(n)))==Set(Vec(Str(n^3))) \\ Charles R Greathouse IV, Jun 28 2011

A232662 Numbers n such that n and n^7 have the same set of digits.

Original entry on oeis.org

0, 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 12635940, 26875130, 29851046, 31572460, 36082794, 38625410, 39756810, 42675139, 47025831, 50748936, 58291760, 65279801, 68249735, 76942451, 78952160, 80572614, 100000000, 102359784, 102374865
Offset: 1

Views

Author

Arkadiusz Wesolowski, Nov 27 2013

Keywords

Examples

			{0, 1, 2, 3, 4, 5, 6, 9} - the set of digits of 12635940 and of 12635940^7, so 12635940 is in the sequence.
		

Crossrefs

Programs

  • PARI
    for(n=0, 102374865, if(Set(Vec(Str(n)))==Set(Vec(Str(n^7))), print1(n, ", ")));

A232660 Numbers n such that n and n^5 have the same set of digits.

Original entry on oeis.org

0, 1, 10, 100, 1000, 10000, 39568, 100000, 395680, 1000000, 2114325, 2751490, 3246105, 3956800, 4356891, 4768209, 4926051, 6274019, 8021439, 10000000, 10267394, 10352849, 10368279, 10456932, 10478632, 10489723, 10489725, 10527934, 10567293, 10639428, 10827439
Offset: 1

Views

Author

Arkadiusz Wesolowski, Nov 27 2013

Keywords

Examples

			{3, 5, 6, 8, 9} - the set of digits of 39568 and of 39568^5, so 39568 is in the sequence.
		

Crossrefs

Programs

  • Magma
    [n : n in [0..10827439] | Set(Intseq(n)) eq Set(Intseq(n^5))];
    
  • PARI
    for(n=0, 10827439, if(Set(Vec(Str(n)))==Set(Vec(Str(n^5))), print1(n, ", ")));

A232661 Numbers n such that n and n^6 have the same set of digits.

Original entry on oeis.org

0, 1, 10, 100, 1000, 10000, 100000, 1000000, 1380796, 10000000, 10423786, 10489362, 10532689, 10689247, 10743958, 12645980, 13042697, 13674925, 13807960, 14205893, 14857690, 16892043, 17284360, 17983256, 19046537, 19754203, 20634971, 20637451, 21865409
Offset: 1

Views

Author

Arkadiusz Wesolowski, Nov 27 2013

Keywords

Examples

			{0, 1, 3, 6, 7, 8, 9} - the set of digits of 1380796 and of 1380796^6, so 1380796 is in the sequence.
		

Crossrefs

Programs

  • PARI
    for(n=0, 21865409, if(Set(Vec(Str(n)))==Set(Vec(Str(n^6))), print1(n, ", ")));

A232712 Least positive k (not a power of 10) such that k and k^n have the same set of digits.

Original entry on oeis.org

2, 4762, 107624, 35641, 39568, 1380796, 12635940, 40837596, 102349857, 102567384, 106342987, 129046873, 107623945, 231940678, 239607415, 368709154, 1023456789, 164758903, 176384592, 1023456789, 1023456789, 1023456789, 1023456789, 1023456789, 1023456789
Offset: 1

Views

Author

Arkadiusz Wesolowski, Nov 28 2013

Keywords

Comments

a(17) and a(20)-a(40) = A050278(1) = 1023456789, the smallest pandigital number. [Lars Blomberg, Dec 10 2013]

Crossrefs

Programs

  • PARI
    for(n=1, 6, k=1; until(Set(Vec(Str(k)))==Set(Vec(Str(k^n)))&&!(sumdigits(k)==1), k++); print1(k, ", "));

Extensions

a(14)-a(25) from Lars Blomberg, Dec 10 2013
Showing 1-6 of 6 results.