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 18 results. Next

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

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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

A178501 Zero followed by powers of ten.

Original entry on oeis.org

0, 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000, 1000000000, 10000000000, 100000000000, 1000000000000, 10000000000000, 100000000000000, 1000000000000000, 10000000000000000, 100000000000000000, 1000000000000000000, 10000000000000000000, 100000000000000000000
Offset: 0

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Author

Reinhard Zumkeller, May 28 2010

Keywords

Comments

The sequence S consisting of the nonnegative numbers arranged in lexicographic order according to their decimal expansion begins 0, 1, 10, 100, 1000, ..., 2, 20, 200, 2000, ..., 3, 30, ... does not have an OEIS entry, since there are uncountably many terms before 2 appears (or even before 100000010000 appears). However, S does begin with the present sequence. - N. J. A. Sloane, Dec 09 2024
a(n)^k + reverse(a(n))^k is a palindrome for any positive integer k. - Bui Quang Tuan, Mar 31 2015

Crossrefs

Cf. A093136, A131577, A140429, A178500; subsequence of A029793.
The powers of 10, A011557, is a subsequence.

Programs

Formula

a(n+1) = A011557(n).
a(n) = A178500(n)/10.
From Paul Barry, Jul 09 2003: (Start)
a(n) = (10^n - 0^n)/10.
E.g.f.: exp(5*x)*sinh(5*x)/5.
Binomial transform of A015577. (End)
G.f.: x/(1 - 10*x). - Chai Wah Wu, Jun 17 2020
From Elmo R. Oliveira, Jul 21 2025: (Start)
a(n) = 10*a(n-1) for n > 1.
a(n) = A093136(n)/2 for n >= 1. (End)

Extensions

More terms from Elmo R. Oliveira, Jul 21 2025

A232659 Numbers n such that n and n^4 have the same set of digits.

Original entry on oeis.org

0, 1, 10, 100, 1000, 10000, 35641, 100000, 129486, 146980, 356410, 465780, 1000000, 1059281, 1083749, 1206794, 1239876, 1245890, 1265360, 1294860, 1297853, 1348970, 1469800, 1486920, 1495860, 1567038, 1572086, 1574689, 1956740, 2035817, 2084615, 2114760
Offset: 1

Views

Author

Arkadiusz Wesolowski, Nov 27 2013

Keywords

Examples

			{1, 3, 4, 5, 6} - the set of digits of 35641 and of 35641^4, so 35641 is in the sequence.
		

Crossrefs

Programs

  • Magma
    [n : n in [0..2114760] | Set(Intseq(n)) eq Set(Intseq(n^4))];
    
  • Mathematica
    Select[Range[0,22*10^5],Union[IntegerDigits[#]]== Union[ IntegerDigits[ #^4]]&] (* Harvey P. Dale, Aug 02 2016 *)
  • PARI
    for(n=0, 2114760, if(Set(Vec(Str(n)))==Set(Vec(Str(n^4))), print1(n, ", ")));

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, ", ")));

A029797 Numbers k such that k^2 and k^3 have the same set of digits.

Original entry on oeis.org

0, 1, 10, 100, 146, 1000, 1203, 1460, 7652, 8077, 8751, 8965, 10000, 10406, 11914, 12030, 12057, 12586, 12768, 12961, 13055, 14202, 14600, 14625, 16221, 19350, 20450, 21539, 22040, 22175, 23682, 24071, 25089, 25201, 25708, 26653, 26981
Offset: 1

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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]
This conjecture is false. If the conjecture is true then for some N we would have k is in the sequence if k >= n. But 10^e + 1 (A062397) is not in the sequence for any integer e >= 0. - David A. Corneth, Nov 13 2023

Examples

			146 is in the sequence as 146^2 = 21316 has digits {1, 2, 3, 6} and 146^3 = 3112136 has digits {1, 2, 3, 6} as well. - _David A. Corneth_, Nov 13 2023
		

Crossrefs

Cf. A011557 (a subsequence).

Programs

A257763 Zeroless numbers n such that n and n^2 have the same set of decimal digits.

Original entry on oeis.org

1, 4762, 4832, 12385, 14829, 26394, 34196, 36215, 49827, 68474, 72576, 74528, 79286, 79836, 94583, 94867, 96123, 98376, 123385, 123546, 124235, 124365, 124579, 124589, 125476, 125478, 126969, 129685, 135438, 139256, 139261, 139756, 149382, 152385, 156242
Offset: 1

Views

Author

Alois P. Heinz, May 07 2015

Keywords

Examples

			4762 is in the sequence because it is zeroless and 4762^2 = 22676644 has the same set of decimal digits as 4762: {2,4,6,7}.
		

Crossrefs

Programs

  • Maple
    a:= proc(n) option remember; local k, s;
          for k from 1+`if`(n=1, 0, a(n-1)) do
            s:= {convert(k, base, 10)[]};
            if not 0 in s and s={convert(k^2, base, 10)[]}
               then return k fi
          od
        end:
    seq(a(n), n=1..10);
  • Mathematica
    sameQ[n_]:=Union[IntegerDigits[n]]==Union[IntegerDigits[n^2]];Select[Range@156242,And[FreeQ[IntegerDigits[#],0],sameQ[#]]&] (* Ivan N. Ianakiev, May 08 2015 *)
  • PARI
    isok(n) = vecmin(d=digits(n)) && Set(d) == Set(digits(n^2)); \\ Michel Marcus, May 31 2015
  • Python
    A257763_list = [n for n in range(1,10**6) if not '0' in str(n) and set(str(n)) == set(str(n**2))] # Chai Wah Wu, May 31 2015
    

Formula

{A029793} intersect {A052382}.

A257760 Zeroless numbers n such that the products of the decimal digits of n and n^2 coincide.

Original entry on oeis.org

1, 1488, 3381, 14889, 18489, 181965, 262989, 338646, 358489, 367589, 437189, 438329, 479285, 781839, 964941, 1456589, 1763954, 2579285, 2868489, 3365285, 3419389, 3451988, 3584889, 3625619, 4378829, 4653989, 6868877, 7295986, 9548479, 14529839, 14534488
Offset: 1

Views

Author

Pieter Post, May 07 2015

Keywords

Comments

It is unknown if this sequence is infinite.
Number of terms < 10^n: 1, 1, 1, 3, 5, 15, 29, 75, 211, 583, 1694, ..., . - Robert G. Wilson v, May 25 2015
Also nontrivial numbers n such that the products of the decimal digits of n and n^2 are equal. Trivial solutions are any number which contains a zero in its decimal expansion. - Robert G. Wilson v, May 11 2015

Examples

			1488 is in the sequence since 1488^2 = 2214144 and we have 256 = 1*4*8*8 = 2*2*1*4*1*4*4.
3381 is in the sequence because 3381^2 = 11431161 and 72 = 3*3*8*1 = 1*1*4*3*1*1*6*1.
		

Crossrefs

Subsequence of A052040.

Programs

  • Mathematica
    fQ[n_] := Times @@ IntegerDigits[n] == Times @@ IntegerDigits[n^2] > 0; Select[ Range@ 10000000, fQ] (* Robert G. Wilson v, May 07 2015 *)
  • PARI
    isok(n) = (d = digits(n)) && vecmin(d) && (dd = digits(n^2)) && (prod(k=1, #d, d[k]) == prod(k=1, #dd, dd[k])); \\ Michel Marcus, May 07 2015

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, ", ")));

A030091 Primes such that p and p^2 have same set of digits.

Original entry on oeis.org

94583, 100469, 102953, 107251, 110923, 184903, 279863, 285101, 406951, 459521, 493621, 499423, 504821, 684581, 752681, 758141, 758941, 786431, 836291, 843701, 928637, 976513, 980261, 1008947, 1009859, 1024399, 1029647
Offset: 1

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Author

Keywords

Crossrefs

Programs

  • Haskell
    import Data.List (nub, sort)
    import Data.Function (on)
    a030091 n = a030091_list !! (n-1)
    a030091_list =
       filter (\x -> ((==) `on` (nub . sort . show)) x (x^2)) a000040_list
    -- Reinhard Zumkeller, Aug 11 2011
  • Mathematica
    Select[Prime[Range[82000]],Union[IntegerDigits[#]]== Union[ IntegerDigits [#^2]]&] (* Harvey P. Dale, Aug 12 2011 *)
  • PARI
    isA030091(n)=isprime(n)&&Set(Vec(Str(n)))==Set(Vec(Str(n^2))) \\ Charles R Greathouse IV, Jun 28 2011
    

Formula

Equals A000040 INTERSECTION A029793. - Jonathan Vos Post, Jul 06 2008
Showing 1-10 of 18 results. Next