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 1-3 of 3 results.

A296712 Numbers whose base-10 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, 11, 22, 33, 44, 55, 66, 77, 88, 99, 101, 102, 103, 104, 105, 106, 107, 108, 109, 111, 120, 121, 130, 131, 132, 140, 141, 142, 143, 150, 151, 152, 153, 154, 160, 161, 162, 163, 164, 165, 170, 171, 172, 173, 174, 175, 176, 180, 181
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 A296712-A296714 partition the natural numbers.
****
Guide to related sequences:
Base #(rises) = #(falls) #(rises) > #(falls) #(rises) < #(falls)
2 A005408 (none) A005843

Examples

			The base-10 digits of 181 are 1,8,1; here #(rises) = 1 and #(falls) = 1, so 181 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 10; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296712 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296713 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296714 *)

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 *)

A296696 Numbers whose base-4 digits d(m), d(m-1), ... d(0) have #(rises) < #(falls); see Comments.

Original entry on oeis.org

4, 8, 9, 12, 13, 14, 16, 20, 32, 36, 37, 40, 41, 48, 52, 53, 56, 57, 58, 60, 61, 62, 64, 68, 72, 73, 76, 77, 78, 80, 84, 100, 116, 120, 121, 128, 132, 136, 137, 140, 141, 142, 144, 145, 146, 147, 148, 149, 152, 153, 156, 157, 158, 160, 164, 165, 168, 169
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 196 are 3,0,1,0; here #(rises) = 1 and #(falls) = 2, so 196 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 *)

Extensions

Example corrected by Harvey P. Dale, Sep 04 2018
Showing 1-3 of 3 results.