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.

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.
		

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

A102488 Numbers in base-12 representation that cannot be written with decimal digits.

Original entry on oeis.org

10, 11, 22, 23, 34, 35, 46, 47, 58, 59, 70, 71, 82, 83, 94, 95, 106, 107, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 154, 155, 166, 167, 178, 179, 190, 191, 202, 203, 214
Offset: 1

Views

Author

Reinhard Zumkeller, Jan 12 2005

Keywords

Examples

			143 = 11*12^1 + 11*12^0 = 'BB', therefore 143 is a term.
		

Crossrefs

Complement of A102487; A102490, A102492, A102494.

Programs

  • Haskell
    import Data.List (unfoldr)
    a102488 n = a102488_list !! (n-1)
    a102488_list = filter (any (> 9) . unfoldr (\x ->
       if x == 0 then Nothing else Just $ swap $ divMod x 12)) [1..]
    -- Reinhard Zumkeller, Apr 18 2011
  • Mathematica
    Select[Range[250],Max[IntegerDigits[#,12]]>9&] (* Harvey P. Dale, Oct 20 2020 *)

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.
		

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 *)

A102493 Numbers in base-60 representation that can be written with decimal digits.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 300, 301, 302, 303, 304, 305, 306, 307, 308
Offset: 1

Views

Author

Reinhard Zumkeller, Jan 12 2005

Keywords

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.

Crossrefs

Complement of A102494; A102487, A102489, A102491.

Programs

  • Haskell
    import Data.List (unfoldr)
    a102493 n = a102493_list !! (n-1)
    a102493_list = filter (all (<= 9) . unfoldr
       (\x -> if x == 0 then Nothing else Just $ swap $ divMod x 60)) [0..]
    -- Reinhard Zumkeller, Jun 27 2013
  • Mathematica
    Table[Range[60n,60n+9],{n,0,6}]//Flatten (* Harvey P. Dale, Jul 06 2024 *)
Showing 1-4 of 4 results.