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.

A296708 Numbers whose base-8 digits d(m), d(m-1), ..., d(0) have #(rises) < #(falls); see Comments.

Original entry on oeis.org

8, 16, 17, 24, 25, 26, 32, 33, 34, 35, 40, 41, 42, 43, 44, 48, 49, 50, 51, 52, 53, 56, 57, 58, 59, 60, 61, 62, 64, 72, 128, 136, 137, 144, 145, 192, 200, 201, 208, 209, 210, 216, 217, 218, 256, 264, 265, 272, 273, 274, 280, 281, 282, 283, 288, 289, 290, 291
Offset: 1

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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 A296706-A296707 partition the natural numbers. See the guide at A296712.

Examples

			The base-8 digits of 291 are 4,4,3; here #(rises) = 0 and #(falls) = 1, so 291 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 8; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296706 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296707 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296708 *)