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 16 results. Next

A044821 Positive integers having distinct base-10 run lengths.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 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
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			117 is in the sequence because it has a run length of 2 and a run length of 1. 101 is not in the sequence because it has three run lengths of 1. - _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:
isA044821 := proc(n)
    local dgs,rl;
    dgs := convert(n,base,10) ;
    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 isA044821(n) then
        printf("%d,",n) ;
    end if;
end do: # R. J. Mathar, Jan 18 2018
  • PARI
    is(n) = { my(runs = List(), lr = 0, d = digits(n)); for(i = 1, #d - 1, if(d[i] != d[i + 1], listput(runs, i - lr); lr = i; ) ); listput(runs, #d - lr); #Set(runs) == #runs } \\ David A. Corneth, Jan 04 2021
  • Python
    from itertools import groupby
def ok(n):
  runlengths = [len(list(g)) for k, g in groupby(str(n))]
  return len(runlengths) == len(set(runlengths))
print([i for i in range(1, 256) if ok(i)]) # Michael S. Branicky, Jan 04 2021

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).

A044824 Positive integers having distinct base-13 run lengths.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 28, 42, 56, 70, 84, 98, 112, 126, 140, 154, 168, 169, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 197, 211, 225, 239, 253, 267, 281, 295, 309, 323, 337, 338, 352, 364, 365, 366, 367, 368, 369, 370, 371
Offset: 1

Views

Author

Clark Kimberling

Keywords

Examples

			338 = 200_13 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).

Programs

  • Mathematica
    Select[Range[400],Union[Tally[Length/@Split[IntegerDigits[#,13]]][[All,2]]] == {1}&] (* Harvey P. Dale, Sep 15 2020 *)
Showing 1-10 of 16 results. Next

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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