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.

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