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.

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A296888 Numbers whose base-12 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, 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, 60, 61, 62, 63, 64, 65, 66, 67
Offset: 1

Views

Author

Clark Kimberling, Jan 10 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 A296888-A296890 partition the natural numbers. See the guides at A296712 and A296882.

Examples

			The base-12 digits of 2030 are 1,2,1,2; here #(pits) = 1 and #(peaks) = 1, so 2030 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 12;
    d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
    Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296888 *)
    Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296889 *)
    Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296890 *)

A296891 Numbers whose base-13 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, 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, 60, 61, 62, 63, 64, 65, 66, 67
Offset: 1

Views

Author

Clark Kimberling, Jan 10 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 A296891-A296894 partition the natural numbers. See the guides at A296712 and A296882.

Examples

			The base-13 digits of 2550 are 1,2,1,2; here #(pits) = 1 and #(peaks) = 1, so 2550 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 13;
    d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
    Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296891 *)
    Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296892 *)
    Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296893 *)

A296900 Numbers whose base-16 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, 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, 60, 61, 62, 63, 64, 65, 66, 67
Offset: 1

Views

Author

Clark Kimberling, Jan 12 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 A296900-A296902 partition the natural numbers. See the guides at A296712 and A296882.

Examples

			The base-16 digits of 4626 are 1,2,1,2; here #(pits) = 1 and #(peaks) = 1, so 4626 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 16;
    d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
    Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296900 *)
    Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296901 *)
    Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296902 *)

A296903 Numbers whose base-20 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, 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, 60, 61, 62, 63, 64, 65, 66, 67
Offset: 1

Views

Author

Clark Kimberling, Jan 12 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 A296903-A296905 partition the natural numbers.
a(n) = n for n = 1..400, but not for n = 401. See the guides at A296712 and A296882.

Examples

			The base-20 digits of 8822 are 1,2,1,2; here #(pits) = 1 and #(peaks) = 1, so 8822 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 20;
    d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
    Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296903 *)
    Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296904 *)
    Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296905 *)

A296906 Numbers whose base-60 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, 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, 60, 61, 62, 63, 64, 65, 66, 67
Offset: 1

Views

Author

Clark Kimberling, Jan 12 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 A296906..A296908 partition the natural numbers.
a(n) = n for n = 1..3600, but not for n = 3601. See the guides at A296712 and A296882.

Examples

			The base-60 digits of 223262 are 1,2,1,2; here #(pits) = 1 and #(peaks) = 1, so 223262 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 60;
    d[n_] := Differences[Sign[Differences[IntegerDigits[n, b]]]];
    Select[Range [z], Count[d[#], -2] == Count[d[#], 2] &]  (* A296906 *)
    Select[Range [z], Count[d[#], -2] < Count[d[#], 2] &]   (* A296907 *)
    Select[Range [z], Count[d[#], -2] > Count[d[#], 2] &]   (* A296908 *)

A296691 Numbers whose base-3 digits d(m), d(m-1), ... d(0) have #(rises) = #(falls); see Comments.

Original entry on oeis.org

1, 2, 4, 8, 10, 11, 13, 15, 16, 19, 20, 23, 26, 28, 29, 31, 35, 37, 38, 40, 42, 43, 45, 49, 51, 52, 55, 56, 58, 62, 68, 71, 73, 74, 77, 80, 82, 83, 85, 89, 91, 92, 94, 96, 97, 100, 101, 104, 107, 109, 110, 112, 116, 118, 119, 121, 123, 124, 126, 130, 132
Offset: 1

Views

Author

Clark Kimberling, Dec 19 2017

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 A296691-A296693 partition the natural numbers. See the guide at A296712.

Examples

			The base-3 digits of 132 are 1,1,2,2,0; here #(rises) = #(falls) = 1, so 132 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 3; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296691 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296692 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296693 *)

A296692 Numbers whose base-3 digits d(m), d(m-1), ... d(0) have #(rises) > #(falls); see Comments.

Original entry on oeis.org

5, 14, 17, 32, 41, 44, 46, 47, 50, 53, 59, 86, 95, 98, 113, 122, 125, 127, 128, 131, 134, 136, 137, 139, 140, 143, 149, 152, 154, 155, 158, 161, 167, 176, 179, 221, 248, 257, 260, 275, 284, 287, 289, 290, 293, 296, 302, 329, 338, 341, 356, 365, 368, 370, 371
Offset: 1

Views

Author

Clark Kimberling, Dec 19 2017

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 A296691-A296693 partition the natural numbers. See the guide at A296712.

Examples

			The base-3 digits of 371 are 1,1,1,2,0,2; here #(rises) = 2 and #(falls) = 1, so 371 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 3; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296691 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296692 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296693 *)

A296693 Numbers whose base-3 digits d(m), d(m-1), ... d(0) have #(rises) < #(falls); see Comments.

Original entry on oeis.org

3, 6, 7, 9, 12, 18, 21, 22, 24, 25, 27, 30, 33, 34, 36, 39, 48, 54, 57, 60, 61, 63, 64, 65, 66, 67, 69, 70, 72, 75, 76, 78, 79, 81, 84, 87, 88, 90, 93, 99, 102, 103, 105, 106, 108, 111, 114, 115, 117, 120, 129, 144, 147, 156, 162, 165, 168, 169, 171, 174
Offset: 1

Views

Author

Clark Kimberling, Dec 19 2017

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 A296691-A296693 partition the natural numbers. See the guide at A296712.

Examples

			The base-3 digits of 174 are 2,0,1,1,0; here #(rises) = 1 and #(falls) = 2, so 174 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 3; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296691 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296692 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296693 *)
    rltfQ[n_]:=Module[{d=Differences[IntegerDigits[n,3]]},Count[d,?(#>0&)]<Count[d,?(#<0&)]]; Select[Range[200],rltfQ] (* Harvey P. Dale, Sep 25 2019 *)

A296694 Numbers whose base-4 digits d(m), d(m-1), ... d(0) have #(rises) = #(falls); see Comments.

Original entry on oeis.org

1, 2, 3, 5, 10, 15, 17, 18, 19, 21, 24, 25, 28, 29, 30, 33, 34, 35, 38, 39, 42, 44, 45, 46, 49, 50, 51, 54, 55, 59, 63, 65, 66, 67, 69, 74, 79, 81, 82, 83, 85, 88, 89, 92, 93, 94, 96, 101, 104, 105, 112, 117, 122, 124, 125, 126, 129, 130, 131, 133, 138, 143
Offset: 1

Views

Author

Clark Kimberling, Dec 21 2017

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 A296694-A296696 partition the natural numbers. See the guide at A296712.

Examples

			The base-4 digits of 143 are 2,0,3,3; here #(rises) = 1 and #(falls) = 1, so 143 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 4; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296694 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296695 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296696 *)

A296695 Numbers whose base-4 digits d(m), d(m-1), ... d(0) have #(rises) > #(falls); see Comments.

Original entry on oeis.org

6, 7, 11, 22, 23, 26, 27, 31, 43, 47, 70, 71, 75, 86, 87, 90, 91, 95, 97, 98, 99, 102, 103, 106, 107, 108, 109, 110, 111, 113, 114, 115, 118, 119, 123, 127, 134, 135, 139, 155, 171, 175, 177, 178, 179, 182, 183, 187, 191, 198, 199, 203, 219, 262, 263, 267
Offset: 1

Views

Author

Clark Kimberling, Dec 21 2017

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 A296694-A296696 partition the natural numbers. See the guide at A296712.

Examples

			The base-4 digits of 267 are 1,0,0,2,3; here #(rises) = 2 and #(falls) = 1, so 267 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 4; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296694 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296695 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296696 *)
Previous Showing 21-30 of 115 results. Next