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.

A043703 Numbers whose base-14 representation has an even number of runs.

Original entry on oeis.org

14, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 76, 77, 78
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A299174, A043692, A043693, A043694, A043695, A043696, A043697, A043698, A043700, A043701, A043702, A043703, A043704, A043705.
Cf. A043717 (complement).

Programs

  • Mathematica
    Select[Range[80],EvenQ[Length[Split[IntegerDigits[#,14]]]]&] (* Harvey P. Dale, Aug 30 2020 *)
  • PARI
    is(n) = qstreaks(n)%2 == 0
qstreaks(n, {b = 14}) = {my(d = digits(n, b)); sum(i = 2, #d, d[i]!=d[i-1])+1} \\ David A. Corneth, Aug 31 2020

A043631 Numbers whose base-9 representation has exactly 2 runs.

Original entry on oeis.org

9, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 24, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 48, 49, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 71, 72, 73, 74, 75, 76, 77, 78, 79, 81, 90, 92, 93, 94, 95
Offset: 1

Views

Author

Clark Kimberling

Keywords

Links

Crossrefs

Cf. A007095.
Subsequence of A043698.

Programs

  • Maple
    rlen := proc(n,ba) local rs,s,dgs,i ; rs :=0 ; s := 0; dgs := convert(n,base,ba) ; for i from 1 to nops(dgs) do if s = 0 then s :=1 ; else if op(i,dgs) <> op(i-1,dgs) then rs := rs+1 ; s :=1 ; else s :=s+1 ; fi; fi; od: rs := rs+1 ; RETURN (rs) ; end: for n from 1 to 200 do if rlen(n,9) = 2 then printf("%d,",n) ; fi; od: # R. J. Mathar, Oct 20 2008
  • Mathematica
    Select[Range[100],Length[Split[IntegerDigits[#,9]]]==2&] (* Harvey P. Dale, Jan 06 2022 *)

Extensions

Extended by R. J. Mathar, Oct 20 2008

A048306 Numbers whose base-9 expansions, read from left to right, have run lengths that strictly increase.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 20, 30, 40, 50, 60, 70, 80, 81, 91, 101, 111, 121, 131, 141, 151, 161, 162, 172, 182, 192, 202, 212, 222, 232, 242, 243, 253, 263, 273, 283, 293, 303, 313, 323, 324, 334, 344, 354, 364, 374, 384, 394, 404, 405, 415, 425, 435, 445
Offset: 0

Views

Author

Patrick De Geest, Feb 15 1999

Keywords

Crossrefs

Cf. A037015, A043698, A043712, A044820, A044958.

A048320 Numbers whose base-9 expansions, read from left to right, have run lengths that strictly decrease.

Original entry on oeis.org

0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 20, 30, 40, 50, 60, 70, 80, 90, 91, 92, 93, 94, 95, 96, 97, 98, 180, 181, 182, 183, 184, 185, 186, 187, 188, 270, 271, 272, 273, 274, 275, 276, 277, 278, 360, 361, 362, 363, 364, 365, 366, 367, 368, 450, 451, 452, 453, 454, 455, 456
Offset: 0

Views

Author

Patrick De Geest, Feb 15 1999

Keywords

Crossrefs

Cf. A037013, A043698, A043712, A044820, A044958.
Showing 1-4 of 4 results.

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

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