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 1-4 of 4 results.

A102487 Numbers in base-12 representation that can be written with decimal digits.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 84, 85, 86
Offset: 1

Views

Author

Reinhard Zumkeller, Jan 12 2005

Keywords

Comments

Numbers that are only in this sequence or only in A039274 but not in both are n= 131, 142, 275, 286, 419, 430 etc: see A039558. [From R. J. Mathar, Aug 30 2008]

Links

Crossrefs

Complement of A102488; A102489, A102491, A102493.
Cf. A033048 (subsequence).

Programs

  • Haskell
    import Data.List (unfoldr)
a102487 n = a102487_list !! (n-1)
a102487_list = filter (all (< 10) . unfoldr (\x ->
   if x == 0 then Nothing else Just $ swap $ divMod x 12)) [0..]
-- Reinhard Zumkeller, Apr 18 2011
  • Mathematica
    fQ[n_] := Last@ Union@ IntegerDigits[n, 12] < 10; Select[ Range[0, 86], fQ] (* Robert G. Wilson v, Apr 17 2012 *)
  • PARI
    {for(testn=0,87,
lgt=1;
for(i=1,1000,if(12^i > testn,lgt=i;break()));
atst=testn;pasr=1;
for(j=1,lgt,lasd=atst%12;
if(lasd<10,atst=(atst-lasd)/12,pasr=0;break()));
if(pasr==1,print1(testn,", ")))}
\\ Douglas Latimer, Apr 17 2012
  • Python
    A102487_list = [int(str(x), 12) for x in range(10**6)] # Chai Wah Wu, Apr 09 2016

A102490 Numbers in base-16 representation that cannot be written with decimal digits.

Original entry on oeis.org

10, 11, 12, 13, 14, 15, 26, 27, 28, 29, 30, 31, 42, 43, 44, 45, 46, 47, 58, 59, 60, 61, 62, 63, 74, 75, 76, 77, 78, 79, 90, 91, 92, 93, 94, 95, 106, 107, 108, 109, 110, 111, 122, 123, 124, 125, 126, 127, 138, 139, 140, 141, 142, 143, 154, 155, 156, 157, 158, 159, 160
Offset: 1

Views

Author

Reinhard Zumkeller, Jan 12 2005

Keywords

Examples

			42 = 2*16^1 + 10*16^0 = '2A', therefore 42 is a term.

Links

Crossrefs

Complement of A102489; A102488, A102492, A102494.

Programs

  • Haskell
    import Data.List (unfoldr)
a102490 n = a102490_list !! (n-1)
a102490_list = filter (any (> 9) . unfoldr
   (\x -> if x == 0 then Nothing else Just $ swap $ divMod x 16)) [0..]
-- Reinhard Zumkeller, Jun 27 2013
  • Mathematica
    Select[Range[200],IntegerLength[Max[IntegerDigits[#,16]]]>1&] (* Harvey P. Dale, Jun 12 2020 *)
  • Python
    def ok(n): return any(hd > '9' for hd in hex(n)[2:])
print(list(filter(ok, range(161)))) # Michael S. Branicky, Oct 11 2021

A102492 Numbers in base-20 representation that cannot be written with decimal digits.

Original entry on oeis.org

10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 130, 131, 132, 133
Offset: 1

Views

Author

Reinhard Zumkeller, Jan 12 2005

Keywords

Examples

			112 = 5*20^1 + 12*20^0 = '5C', therefore 112 is a term.

Links

Crossrefs

Complement of A102491; A102488, A102490, A102494.

Programs

  • Haskell
    import Data.List (unfoldr)
a102492 n = a102492_list !! (n-1)
a102492_list = filter (any (> 9) . unfoldr
   (\x -> if x == 0 then Nothing else Just $ swap $ divMod x 20)) [0..]
-- Reinhard Zumkeller, Jun 27 2013
  • Mathematica
    Select[Range[150],Max[IntegerDigits[#,20]]>9&] (* Harvey P. Dale, Mar 27 2021 *)

A102494 Numbers in base-60 representation that cannot be written with decimal digits.

Original entry on oeis.org

10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88
Offset: 1

Views

Author

Reinhard Zumkeller, Jan 12 2005

Keywords

Examples

			200 = 3*60^1 + 20*60^0 = '3K', therefore 200 is a term.

References

  • Mohammad K. Azarian, Meftah al-hesab: A Summary, MJMS, Vol. 12, No. 2, Spring 2000, pp. 75-95. Mathematical Reviews, MR 1 764 526. Zentralblatt MATH, Zbl 1036.01002.
  • Mohammad K. Azarian, A Summary of Mathematical Works of Ghiyath ud-din Jamshid Kashani, Journal of Recreational Mathematics, Vol. 29(1), pp. 32-42, 1998.

Links

Crossrefs

Complement of A102493; A102488, A102490, A102492.

Programs

  • Haskell
    import Data.List (unfoldr)
a102494 n = a102494_list !! (n-1)
a102494_list = filter (any (> 9) . unfoldr
   (\x -> if x == 0 then Nothing else Just $ swap $ divMod x 60)) [0..]
-- Reinhard Zumkeller, Jun 27 2013
  • Mathematica
    Select[Range[100],Max[IntegerDigits[#,60]]>9&] (* Harvey P. Dale, Dec 27 2012 *)
Showing 1-4 of 4 results.

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