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.

Previous Showing 51-60 of 115 results. Next

A296756 Numbers whose base-15 digits d(m), d(m-1), ..., d(0) have #(rises) = #(falls); see Comments.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 32, 48, 64, 80, 96, 112, 128, 144, 160, 176, 192, 208, 224, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239, 241, 255, 256, 270, 271, 272, 285, 286, 287, 288, 300, 301, 302, 303, 304
Offset: 1

Views

Author

Clark Kimberling, Jan 08 2018

Keywords

Comments

A rise is an index i such that d(i) < d(i+1); a fall is an index i such that d(i) > d(i+1). The sequences A296756-A296758 partition the natural numbers. See the guide at A296712.

Examples

			The base-15 digits of 2^20 are 1, 5, 10, 10, 5, 1; here #(rises) = 2 and #(falls) = 2, so 2^20 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 15; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296756 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296757 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296758 *)

A296759 Numbers whose base-16 digits d(m), d(m-1), ..., d(0) have #(rises) = #(falls); see Comments.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 34, 51, 68, 85, 102, 119, 136, 153, 170, 187, 204, 221, 238, 255, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 273, 288, 289, 304, 305, 306, 320, 321, 322, 323, 336, 337
Offset: 1

Views

Author

Clark Kimberling, Jan 08 2018

Keywords

Comments

A rise is an index i such that d(i) < d(i+1); a fall is an index i such that d(i) > d(i+1). The sequences A296759-A296761 partition the natural numbers. See the guide at A296712.

Examples

			The base-16 digits of 2^20 + 1 are 1, 0, 0, 0, 0, 1; here #(rises) = 1 and #(falls) = 1, so 2^20 + 1 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 16; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296759 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296760 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296761 *)
    Select[Range[400],Total[Sign[Differences[IntegerDigits[#,16]]]]==0&] (* Harvey P. Dale, Aug 11 2021 *)

A296763 Numbers whose base-20 digits d(m), d(m-1), ..., d(0) have #(rises) > #(falls); see Comments.

Original entry on oeis.org

22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98
Offset: 1

Views

Author

Clark Kimberling, Jan 08 2018

Keywords

Comments

A rise is an index i such that d(i) < d(i+1); a fall is an index i such that d(i) > d(i+1). The sequences A296762-A296764 partition the natural numbers. See the guide at A296712.

Examples

			The base-20 digits of 98 are 4,18; here #(rises) = 1 and #(falls) = 0, so 98 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 20; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296762 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296763 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296764 *)

A296765 Numbers whose base-60 digits d(m), d(m-1), ..., d(0) have #(rises) = #(falls); see Comments.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 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, 61, 122, 183, 244, 305, 366
Offset: 1

Views

Author

Clark Kimberling, Jan 08 2018

Keywords

Comments

A rise is an index i such that d(i) < d(i+1); a fall is an index i such that d(i) > d(i+1). The sequences A296762-A296764 partition the natural numbers. This sequence differs from A262065; see the example. For a guide to related sequences, see A296712.

Examples

			The base-60 digits of 13406581 are 1, 2, 4, 3, 1; here #(rises) = 2 and #(falls) = 2, so 13406581 is in the sequence.  This sequence is not A262065, as not all the terms in this sequence are palindromes.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 60; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296765 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296766 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296767 *)

A296766 Numbers whose base-60 digits d(m), d(m-1), ..., d(0) have #(rises) > #(falls); see Comments.

Original entry on oeis.org

62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 123
Offset: 1

Views

Author

Clark Kimberling, Jan 08 2018

Keywords

Comments

A rise is an index i such that d(i) < d(i+1); a fall is an index i such that d(i) > d(i+1). The sequences A296762-A296764 partition the natural numbers. See the guide at A296712.

Examples

			The base-60 digits of 223381 are 1, 2, 3, 1; here #(rises) = 2 and #(falls) = 1, so 223381 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 60; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296765 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296766 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296767 *)

A296767 Numbers whose base-60 digits d(m), d(m-1), ..., d(0) have #(rises) < #(falls); see Comments.

Original entry on oeis.org

60, 120, 121, 180, 181, 182, 240, 241, 242, 243, 300, 301, 302, 303, 304, 360, 361, 362, 363, 364, 365, 420, 421, 422, 423, 424, 425, 426, 480, 481, 482, 483, 484, 485, 486, 487, 540, 541, 542, 543, 544, 545, 546, 547, 548, 600, 601, 602, 603, 604, 605, 606
Offset: 1

Views

Author

Clark Kimberling, Jan 08 2018

Keywords

Comments

A rise is an index i such that d(i) < d(i+1); a fall is an index i such that d(i) > d(i+1). The sequences A296762-A296764 partition the natural numbers. See the guide at A296712.

Examples

			The base-60 digits of 10921 are 3, 2, 1; here #(rises) = 0 and #(falls) = 2, so 10921 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 60; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296765 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296766 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296767 *)

A296858 Numbers whose base-2 digits have #(pits) = #(peaks); see Comments.

Original entry on oeis.org

1, 2, 3, 4, 6, 7, 8, 9, 10, 12, 14, 15, 16, 17, 19, 20, 24, 25, 26, 28, 30, 31, 32, 33, 35, 37, 38, 39, 40, 41, 42, 48, 49, 51, 52, 56, 57, 58, 60, 62, 63, 64, 65, 67, 69, 70, 71, 75, 76, 78, 79, 80, 81, 83, 84, 96, 97, 99, 101, 102, 103, 104, 105, 106, 112
Offset: 1

Views

Author

Clark Kimberling, Jan 08 2018

Keywords

Comments

A pit is an index i such that d(i-1) > d(i) < d(i+1); a peak is an index i such that d(i-1) < d(i) > d(i+1). The sequences A296858-A296860 partition the natural numbers. See the guides at A296882 and A296712.

Examples

			The base-2 digits of 112 are 1,1,1,0,0,0,0; here #(pits) = 0 and #(peaks) = 0, so that 112 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 2;
    d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
    Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]   (* A296858 *)
    Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]    (* A296859 *)
    Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]    (* A296860 *)
  • Python
    def cwo(subs, s): # count with overlaps allowed
      c = i = 0
      while i != -1:
        i = s.find(subs, i)
        if i != -1: c += 1; i += 1
      return c
    def ok(n): b = bin(n)[2:]; return cwo('101', b) == cwo('010', b)
    print(list(filter(ok, range(1, 113)))) # Michael S. Branicky, May 11 2021

A296859 Numbers whose base-2 digits have #(pits) > #(peaks); see Comments.

Original entry on oeis.org

5, 11, 13, 21, 22, 23, 27, 29, 43, 44, 45, 46, 47, 53, 54, 55, 59, 61, 77, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 107, 108, 109, 110, 111, 117, 118, 119, 123, 125, 141, 155, 157, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 183, 184, 185, 186
Offset: 1

Views

Author

Clark Kimberling, Jan 09 2018

Keywords

Comments

A pit is an index i such that d(i-1) > d(i) < d(i+1); a peak is an index i such that d(i-1) < d(i) > d(i+1). The sequences A296858-A296860 partition the natural numbers. See the guides at A296882 and A296712.

Examples

			The base-2 digits of 186 are 1,0,1,1,1,0,1,0; here #(pits) = 2 and #(peaks) = 1, so 186 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 2;
    d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
    Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296858 *)
    Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296859 *)
    Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296860 *)
  • Python
    def cwo(subs, s): # count with overlaps allowed
      c = i = 0
      while i != -1:
        i = s.find(subs, i)
        if i != -1: c += 1; i += 1
      return c
    def ok(n): b = bin(n)[2:]; return cwo('101', b) > cwo('010', b)
    print(list(filter(ok, range(1, 187)))) # Michael S. Branicky, May 11 2021

A296860 Numbers k whose base-2 digits d(m), d(m-1), ..., d(0) have #(pits) < #(peaks); see Comments.

Original entry on oeis.org

18, 34, 36, 50, 66, 68, 72, 73, 74, 82, 98, 100, 114, 130, 132, 136, 137, 138, 144, 145, 146, 147, 148, 162, 164, 194, 196, 200, 201, 202, 210, 226, 228, 242, 258, 260, 264, 265, 266, 272, 273, 274, 275, 276, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297
Offset: 1

Views

Author

Clark Kimberling, Jan 09 2018

Keywords

Comments

A pit is an index i such that d(i-1) > d(i) < d(i+1); a peak is an index i such that d(i-1) < d(i) > d(i+1). The sequences A296858-A296860 partition the natural numbers. See the guides at A296882 and A296712.

Examples

			The base-2 digits of 297 are 1, 0, 0, 1, 0, 1, 0, 0, 1; here #(pits) = 1 and #(peaks) = 2, so 297 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 2;
    d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
    Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296858 *)
    Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296859 *)
    Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296860 *)
  • Python
    def cwo(subs, s): # count with overlaps allowed
      c = i = 0
      while i != -1:
        i = s.find(subs, i)
        if i != -1: c += 1; i += 1
      return c
    def ok(n): b = bin(n)[2:]; return cwo('101', b) < cwo('010', b)
    print(list(filter(ok, range(1, 298)))) # Michael S. Branicky, May 11 2021

A296861 Numbers whose base-3 digits d(m), d(m-1), ..., d(0) have #(pits) = #(peaks); see Comments.

Original entry on oeis.org

1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 13, 14, 17, 18, 21, 22, 24, 25, 26, 27, 28, 29, 30, 33, 34, 36, 39, 40, 41, 44, 46, 47, 50, 51, 52, 53, 54, 55, 56, 57, 60, 61, 63, 66, 67, 68, 69, 70, 72, 75, 76, 78, 79, 80, 81, 82, 83, 85, 86, 89, 90, 96, 97, 99, 102, 103
Offset: 1

Views

Author

Clark Kimberling, Jan 09 2018

Keywords

Comments

A pit is an index i such that d(i-1) > d(i) < d(i+1); a peak is an index i such that d(i-1) < d(i) > d(i+1). The sequences A296861-A296863 partition the natural numbers. See the guides at A296882 and A296712.

Examples

			The base-3 digits of 103 are 1, 0, 2, 1, 1; here #(pits) = 1 and #(peaks) = 1, so 103 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 3;
    d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
    Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296861 *)
    Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296862 *)
    Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296863 *)
Previous Showing 51-60 of 115 results. Next