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

A171901 Numbers with at least two identical neighboring digits in their decimal representation.

Original entry on oeis.org

11, 22, 33, 44, 55, 66, 77, 88, 99, 100, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 122, 133, 144, 155, 166, 177, 188, 199, 200, 211, 220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 233, 244, 255, 266, 277, 288, 299, 300, 311, 322, 330, 331, 332, 333
Offset: 1

Views

Author

Reinhard Zumkeller, Feb 07 2010

Keywords

Comments

A171902(n) = a(n+1) - a(n) <= 11.
Complement of A043096; A196368(a(n)) = 0.

Links

Crossrefs

Cf. A044821, A171903, A171904.

Programs

  • Haskell
    import Data.List (elemIndices)
a171901 n = a171901_list !! n
a171901_list = elemIndices 0 a196368_list
-- Reinhard Zumkeller, Oct 29 2001
  • Mathematica
    Select[Range[350],SequenceCount[IntegerDigits[#],{_,x_,x_,_}]>0&] (* The program uses the SequenceCount function from Mathematica version 10 *) (* Harvey P. Dale, May 14 2016 *)
  • Python
    def is_ok(n):
    s = str(n)
    return any(s[i] == s[i - 1] for i in range(1, len(s)))
A171901_list = [n for n in range(400) if is_ok(n)] # Chai Wah Wu, Feb 14 2019

A044817 Positive integers having distinct base-6 run lengths.

Original entry on oeis.org

1, 2, 3, 4, 5, 7, 14, 21, 28, 35, 36, 42, 43, 44, 45, 46, 47, 50, 57, 64, 71, 72, 79, 84, 85, 86, 87, 88, 89, 93, 100, 107, 108, 115, 122, 126, 127, 128, 129, 130, 131, 136, 143, 144, 151, 158, 165, 168, 169, 170, 171, 172, 173, 179, 180, 187, 194, 201, 208, 210, 211
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			93 = 233_6 is in the sequence as it has distinct run lengths of same digits (1, 2). - _David A. Corneth_, Jan 04 2021

Links

Crossrefs

Cf. A044813, A044814, A044815, A044816, A044817, A044818, A044819, A044820, A044821, A044822, A044823, A044824, A044825, A044826, A044827 (base 2 to base 16).

Programs

  • Maple
    filter:= proc(n) local L,R,s,t,i;
  L:= convert(n,base,6);
  R:= NULL; t:= 1; s:= L[1];
  for i from 2 to nops(L) do
    if L[i] <> s then
      R:= R, t; t:= 1; s:= L[i]
    else
      t:= t+1
    fi
  od;
  R:= R, t;
  nops([R]) = nops({R})
end proc:
select(filter, [$1..1000]); # Robert Israel, Jan 17 2018

A044818 Positive integers having distinct base-7 run lengths.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 8, 16, 24, 32, 40, 48, 49, 56, 57, 58, 59, 60, 61, 62, 65, 73, 81, 89, 97, 98, 106, 112, 113, 114, 115, 116, 117, 118, 122, 130, 138, 146, 147, 155, 163, 168, 169, 170, 171, 172, 173, 174, 179, 187, 195, 196, 204, 212, 220, 224, 225, 226, 227, 228
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			40=55_7 has a single run length of 2 and is in the sequence. 211=421_7 has three runs of length 1 as is not in the sequence. - _R. J. Mathar_, Jan 18 2018

Links

Crossrefs

Cf. A044813, A044814, A044815, A044816, A044817, A044818, A044819, A044820, A044821, A044822, A044823, A044824, A044825, A044826, A044827 (base 2 to base 16).

Programs

  • Maple
    rlset := proc(L::list)
    local lset,rl,i ;
    lset := [] ;
    rl := 1 ;
    for i from 2 to nops(L) do
        if op(i,L) = op(i-1,L) then
            rl := rl+1 ;
        else
            lset := [op(lset),rl] ;
            rl := 1;
        end if;
    end do:
    lset := [op(lset),rl] ;
end proc:
isA044818 := proc(n)
    local dgs,rl;
    dgs := convert(n,base,7) ;
    rl := rlset(dgs) ;
    if nops(rl) = nops( convert(rl,set)) then
        true;
    else
        false;
    end if;
end proc:
for n from 1 to 400 do
    if isA044818(n) then
        printf("%d,",n) ;
    end if;
end do: # R. J. Mathar, Jan 18 2018

A044819 Positive integers having distinct base-8 run lengths.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 9, 18, 27, 36, 45, 54, 63, 64, 72, 73, 74, 75, 76, 77, 78, 79, 82, 91, 100, 109, 118, 127, 128, 137, 144, 145, 146, 147, 148, 149, 150, 151, 155, 164, 173, 182, 191, 192, 201, 210, 216, 217, 218, 219, 220, 221, 222, 223, 228, 237, 246, 255, 256
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			222 = 336_8 has a run length of two and a run length of 1, which are distinct lengths, so 222 is in the sequence. - _R. J. Mathar_, Jan 18 2018

Links

Crossrefs

Cf. A044813, A044814, A044815, A044816, A044817, A044818, A044819, A044820, A044821, A044822, A044823, A044824, A044825, A044826, A044827 (base 2 to base 16).

Programs

  • Maple
    rlset := proc(L::list)
    local lset,rl,i ;
    lset := [] ;
    rl := 1 ;
    for i from 2 to nops(L) do
        if op(i,L) = op(i-1,L) then
            rl := rl+1 ;
        else
            lset := [op(lset),rl] ;
            rl := 1;
        end if;
    end do:
    lset := [op(lset),rl] ;
end proc:
isA044819 := proc(n)
    local dgs,rl;
    dgs := convert(n,base,8) ;
    rl := rlset(dgs) ;
    if nops(rl) = nops( convert(rl,set)) then
        true;
    else
        false;
    end if;
end proc:
for n from 1 to 400 do
    if isA044819(n) then
        printf("%d,",n) ;
    end if;
end do: # R. J. Mathar, Jan 18 2018

A044820 Positive integers having distinct base-9 run lengths.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 10, 20, 30, 40, 50, 60, 70, 80, 81, 90, 91, 92, 93, 94, 95, 96, 97, 98, 101, 111, 121, 131, 141, 151, 161, 162, 172, 180, 181, 182, 183, 184, 185, 186, 187, 188, 192, 202, 212, 222, 232, 242, 243, 253, 263, 270, 271, 272, 273, 274, 275, 276
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			242 = 288_9 is in the sequence as it has distinct run lengths of distinct digits (1, 2). - _David A. Corneth_, Jan 04 2021

Links

Crossrefs

Cf. A044813, A044814, A044815, A044816, A044817, A044818, A044819, A044820, A044821, A044822, A044823, A044824, A044825, A044826, A044827 (base 2 to base 16).

Programs

  • Maple
    rlset := proc(L::list)
    local lset,rl,i ;
    lset := [] ;
    rl := 1 ;
    for i from 2 to nops(L) do
        if op(i,L) = op(i-1,L) then
            rl := rl+1 ;
        else
            lset := [op(lset),rl] ;
            rl := 1;
        end if;
    end do:
    lset := [op(lset),rl] ;
end proc:
isA044820 := proc(n)
    local dgs,rl;
    dgs := convert(n,base,9) ;
    rl := rlset(dgs) ;
    if nops(rl) = nops( convert(rl,set)) then
        true;
    else
        false;
    end if;
end proc:
for n from 1 to 400 do
    if isA044820(n) then
        printf("%d,",n) ;
    end if;
end do: # R. J. Mathar, Jan 18 2018

A044814 Positive integers having distinct base-3 run lengths.

Original entry on oeis.org

1, 2, 4, 8, 9, 12, 13, 14, 17, 18, 22, 24, 25, 26, 27, 39, 40, 41, 53, 54, 67, 78, 79, 80, 81, 108, 117, 120, 121, 122, 125, 134, 161, 162, 202, 216, 229, 234, 238, 240, 241, 242, 243, 247, 251, 256, 269, 324, 325, 326, 337, 350, 352, 353, 355, 359, 360, 363, 364
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			18 = 200_3 is in the sequence as it has distinct runs of same base 3 digits (1, 2). - _David A. Corneth_, Jan 04 2021

Links

Crossrefs

Cf. A044813, A044814, A044815, A044816, A044817, A044818, A044819, A044820, A044821, A044822, A044823, A044824, A044825, A044826, A044827 (base 2 to base 16).

A044815 Positive integers having distinct base-4 run lengths.

Original entry on oeis.org

1, 2, 3, 5, 10, 15, 16, 20, 21, 22, 23, 26, 31, 32, 37, 40, 41, 42, 43, 47, 48, 53, 58, 60, 61, 62, 63, 64, 84, 85, 86, 87, 106, 127, 128, 149, 168, 169, 170, 171, 191, 192, 213, 234, 252, 253, 254, 255, 256, 320, 336, 340, 341, 342, 343, 346, 351, 362, 383, 426, 511
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			31 = 133_4 is in the sequence as it has distinct run lengths of same digits (1, 2). - _David A. Corneth_, Jan 04 2021

Links

Crossrefs

Cf. A044813, A044814, A044815, A044816, A044817, A044818, A044819, A044820, A044821, A044822, A044823, A044824, A044825, A044826, A044827 (base 2 to base 16).

A044816 Positive integers having distinct base-5 run lengths.

Original entry on oeis.org

1, 2, 3, 4, 6, 12, 18, 24, 25, 30, 31, 32, 33, 34, 37, 43, 49, 50, 56, 60, 61, 62, 63, 64, 68, 74, 75, 81, 87, 90, 91, 92, 93, 94, 99, 100, 106, 112, 118, 120, 121, 122, 123, 124, 125, 155, 156, 157, 158, 159, 187, 218, 249, 250, 281, 310, 311, 312, 313, 314, 343
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			32 = 112_5 is in the sequence as it has distinct run lengths of same digits (2, 1). - _David A. Corneth_, Jan 04 2021

Crossrefs

Cf. A044813, A044814, A044815, A044816, A044817, A044818, A044819, A044820, A044821, A044822, A044823, A044824, A044825, A044826, A044827 (base 2 to base 16).

A044822 Positive integers having distinct base-11 run lengths.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 121, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 145, 157, 169, 181, 193, 205, 217, 229, 241, 242, 254, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 278, 290, 302, 314, 326
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			270 = 226_11 is in the sequence as it has distinct run lengths of distinct digits (2, 1). - _David A. Corneth_, Jan 04 2021

Links

Crossrefs

Cf. A044813, A044814, A044815, A044816, A044817, A044818, A044819, A044820, A044821, A044822, A044823, A044824, A044825, A044826, A044827 (base 2 to base 16).

A044823 Positive integers having distinct base-12 run lengths.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 26, 39, 52, 65, 78, 91, 104, 117, 130, 143, 144, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 170, 183, 196, 209, 222, 235, 248, 261, 274, 287, 288, 301, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			314 = 222_12 is in the sequence as it has distinct run lengths of distinct digits (1). - _David A. Corneth_, Jan 04 2021

Links

Crossrefs

Cf. A044813, A044814, A044815, A044816, A044817, A044818, A044819, A044820, A044821, A044822, A044823, A044824, A044825, A044826, A044827 (base 2 to base 16).
Showing 1-10 of 18 results. Next

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