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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A199631 Numbers having each digit once and whose cube has each digit three times.

Original entry on oeis.org

4680215379, 4752360918, 4765380219, 4915280637, 5063248197, 5164738920, 5382417906, 5426370189, 5429013678, 5628130974, 5679321048, 5697841320, 5762831940, 5783610492, 5786430129, 5903467821, 6019285734, 6053147982, 6095721483, 6143720958, 6158723094
Offset: 1

Views

Author

T. D. Noe, Nov 09 2011

Keywords

Examples

			4680215379^3 = 102517384602327906545167884939.
		

Crossrefs

Cf. A050278 (pandigital numbers), A199630, A365144, A199632, A199633. Subsequence of A114259.

Programs

  • Mathematica
    t = Select[Permutations[Range[0, 9]], #[[1]] > 0 &]; t2 = Select[t, Union[DigitCount[FromDigits[#]^3]] == {3} &]; FromDigits /@ t2

A199632 Numbers having each digit once and whose 5th power has each digit five times.

Original entry on oeis.org

7351062489, 8105632794, 8401253976, 8731945026, 9164072385, 9238750614, 9615278340, 9847103256
Offset: 1

Views

Author

T. D. Noe, Nov 09 2011

Keywords

Comments

There are 8 numbers total. Subsequence of A114261.

Examples

			7351062489 ^5 = 21465972705539303240727164839587886180361092651449.
		

Crossrefs

Cf. A050278 (pandigital numbers), A199630, A199631, A114260, A114261, A199633.

Programs

  • Mathematica
    t = Select[Permutations[Range[0, 9]], #[[1]] > 0 &]; t2 = Select[t, Union[DigitCount[FromDigits[#]^5]] == {5} &]; FromDigits /@ t2

A199633 Numbers having each digit once and whose 6th power has each digit six times.

Original entry on oeis.org

7025869314, 7143258096, 7931584062, 8094273561, 8920416357, 9247560381
Offset: 1

Views

Author

T. D. Noe, Nov 09 2011

Keywords

Comments

There are 6 numbers total. There are no higher powers with this property.

Examples

			7025869314 ^6 = 120281934463386157260042215510596389732740014997586987548736.
		

Crossrefs

Cf. A050278 (pandigital numbers), A199630, A199631, A365144, A199632.

Programs

  • Mathematica
    t = Select[Permutations[Range[0, 9]], #[[1]] > 0 &]; t2 = Select[t, Union[DigitCount[FromDigits[#]^6]] == {6} &]; FromDigits /@ t2

A134336 Nonnegative integers n containing each digit between n's smallest and largest decimal digits.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 21, 22, 23, 32, 33, 34, 43, 44, 45, 54, 55, 56, 65, 66, 67, 76, 77, 78, 87, 88, 89, 98, 99, 100, 101, 102, 110, 111, 112, 120, 121, 122, 123, 132, 201, 210, 211, 212, 213, 221, 222, 223, 231, 232, 233, 234, 243, 312, 321, 322, 323
Offset: 1

Views

Author

Rick L. Shepherd, Oct 21 2007

Keywords

Comments

A032981 is a subsequence; the term 102 is the first positive integer not also in A032981. A171102 (pandigital numbers) and A033075 are subsequences. Union of A010785 (repdigits) and A108965.
a(n) = A178403(n) for n < 48. - Reinhard Zumkeller, May 27 2010
Equivalently, numbers with the property that the set of its decimal digits is a set of consecutive numbers. - Tanya Khovanova and Charles R Greathouse IV, Jul 31 2012

Crossrefs

Cf. A032981, A050278, A033075 (a subsequence), A010785, A108965.

Programs

  • PARI
    is(n)=my(v=vecsort(eval(Vec(Str(n))),,8));for(i=2,#v,if(v[i]!=1+v[i-1],return(0)));1 \\ Tanya Khovanova and Charles R Greathouse IV, Jul 31 2012
    
  • PARI
    is_A134336(n)={vecmax(n=Set(digits(n)))-vecmin(n)==#n-1} \\ M. F. Hasler, Dec 24 2014
    
  • Python
    def ok(n): d = sorted(set(map(int, str(n)))); return d[-1]-d[0]+1 == len(d)
    print([k for k in range(324) if ok(k)]) # Michael S. Branicky, Dec 12 2023

Formula

a(n) ~ n. - Charles R Greathouse IV, Sep 09 2011

Extensions

Edited by N. J. A. Sloane, Aug 06 2012

A365144 Numbers having each digit once and whose 4th power has each digit four times.

Original entry on oeis.org

5702631489, 7264103985, 7602314895, 7824061395, 8105793624, 8174035962, 8304269175, 8904623175, 8923670541, 9451360827, 9785261403, 9804753612, 9846032571
Offset: 1

Views

Author

T. D. Noe, Nov 09 2011

Keywords

Comments

Currently same terms as A114260, but that sequence has more terms to follow. - Ray Chandler, Aug 23 2023

Examples

			5702631489 is a term since its 4th power 1057550783692741389295697108242363408641 contains four 5's, four 7's, four 0's and so on.
		

Crossrefs

Cf. A050278 (pandigital numbers), A199630, A199631, A199633. Subsequence of A114260.

Programs

  • Mathematica
    t = Select[Permutations[Range[0, 9]], #[[1]] > 0 &]; t2 = Select[t, Union[DigitCount[FromDigits[#]^4]] == {4} &]; FromDigits /@ t2 (* T. D. Noe, Nov 08 2011 *)

A178401 Number of times the rounded up arithmetic mean of digits of n occurs in n, cf. A004427.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 1, 2, 1, 0, 0
Offset: 0

Views

Author

Reinhard Zumkeller, May 27 2010

Keywords

Comments

a(A178402(n)) = 0; a(A050278(n)) = 1; a(A178403(n)) > 0;
a(A010785(n)) > 0; a(A178358(n)) > 0; a(A178359(n)) > 0.

A115922 Numbers k such that k and 2*k, taken together are pandigital.

Original entry on oeis.org

13485, 13548, 13845, 14538, 14685, 14835, 14853, 14865, 15486, 16485, 18546, 18645, 20679, 20769, 20793, 23079, 26709, 26907, 27069, 27093, 27309, 29067, 29073, 29307, 30729, 30792, 30927, 31485, 32079, 32709, 32907, 34851, 35148, 35481, 38145, 38451
Offset: 1

Views

Author

Giovanni Resta, Feb 06 2006

Keywords

Comments

Sequence contains 48 terms, the largest being 48651.
If leading zeros are permitted, there are 12 additional terms: 6729, 6792, 6927, 7269, 7293, 7329, 7692, 7923, 7932, 9267, 9273, 9327. - Harvey P. Dale, Feb 09 2014

Examples

			13485 and 26970=13485*2 together contain all the 10 digits once.
		

Crossrefs

Programs

  • Maple
    for n from 12345 to 49382 do d:=[op(convert(n,base,10)), op(convert(2*n,base,10))]: pandig:=true: for k from 0 to 9 do if(numboccur(k,d)<>1)then pandig:=false: break: fi: od: if(pandig)then print(n): fi: od: # Nathaniel Johnston, May 31 2011
  • Mathematica
    onehalfQ[n_]:=FromDigits[Take[n,5]]/FromDigits[Take[n,-5]]==1/2; FromDigits[ Take[#,5]]&/@Select[Permutations[Range[0,9]],onehalfQ] (* This program generates the full 60-term sequence, with leading zeros permitted, of which this sequence is a subset -- see Comments *) (* Harvey P. Dale, Feb 09 2014 *)
  • PARI
    {for(n=10234,49876,#Set(digits(n))==5||next; #Set(digits(n*2))==5 && #Set(concat(digits(n),digits(n*2)))==10 && print1(n","))} \\ M. F. Hasler, Feb 08 2014

A180489 Smallest pandigital number (A171102) divisible by the n-th prime A000040(n).

Original entry on oeis.org

1023456798, 1023456789, 1023467895, 1023456798, 1024375869, 1023456798, 1023457698, 1023458769, 1023475689, 1023468957, 1023458769, 1023654987, 1023458769, 1023469875, 1023467958, 1023459786, 1023457896, 1023458976
Offset: 1

Views

Author

Lekraj Beedassy, Sep 08 2010

Keywords

Comments

Digits may appear more than once in the multiple, resulting in 11-or-more-digit values of a(n). The first entry for which that happens is a(10545), because the smallest multiple of the 10545th prime 111119 that contains all the digits 0-9 is 92373 * 111119 = 10264395387, and all smaller primes have 10-digit pandigital multiples. - David J. Seal, Sep 18 2017

Examples

			a(1) is the smallest pandigital number divisible by prime(1) = 2, which is 1023456798. - _David J. Seal_, Sep 18 2017
		

Crossrefs

Programs

  • Mathematica
    With[{s = Select[FromDigits@ # & /@ Permutations[Range[0, 9], {10}], # > 10^9 &]}, Table[SelectFirst[s, Divisible[#, Prime@ n] &], {n, 18}]] (* Michael De Vlieger, Sep 18 2017, after Robert G. Wilson v at A171102 *)

A220076 Numbers with exactly six distinct base-10 digits.

Original entry on oeis.org

102345, 102346, 102347, 102348, 102349, 102354, 102356, 102357, 102358, 102359, 102364, 102365, 102367, 102368, 102369, 102374, 102375, 102376, 102378, 102379, 102384, 102385, 102386, 102387, 102389, 102394, 102395, 102396, 102397, 102398, 102435, 102436
Offset: 1

Views

Author

Jonathan Vos Post, Dec 03 2012

Keywords

Comments

This is to A031969 as 6 is to 4. This is the 6th row of the array A(k,n) = n-th number in which the number of distinct base-10 digits is k. A031969 is the 4th row. A220063 is the 5th row. Pandigital numbers A050278 is the 10th row. The subsequence of primes begins: 102359, 102367, 102397, 102437.

Crossrefs

Programs

  • Mathematica
    Select[Range[100000, 103000], Length[Union[IntegerDigits[#]]] == 6 &] (* T. D. Noe, Dec 04 2012 *)

Extensions

Corrected by T. D. Noe, Dec 04 2012

A067898 Least digit not used in n (or 10 if n is pandigital).

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 2, 3, 2, 2
Offset: 0

Views

Author

Rick L. Shepherd, May 13 2003

Keywords

Comments

a(A050278(1)) = a(1023456789) = 10, the first term with that value, as 1023456789 is the first base 10 pandigital number.
a(A052382(n)) = 0; a(A011540(n)) > 0. [Reinhard Zumkeller, May 04 2012]

Examples

			a(10)=2 because decimal digits 0 and 1 are both used in 10, a(102)=3 because decimal digits 0, 1 and 2 are used in 102.
		

Crossrefs

Cf. A050278 (pandigital numbers).
Cf. A212193 (ternary).

Programs

  • Haskell
    import Data.List (delete)
    a067898 n = f n [0..10] where
       f x ys | x <= 9    = head $ delete x ys
              | otherwise = f x' $ delete d ys where (x',d) = divMod x 10
    -- Reinhard Zumkeller, May 04 2012
    
  • Python
    def A067898(n):
        s = set(str(n))
        for i in range(10):
            if str(i) not in s:
                return i
        return 10 # Chai Wah Wu, Apr 13 2024
Previous Showing 31-40 of 85 results. Next