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.

A296749 Numbers whose base-12 digits d(m), d(m-1), ..., d(0) have #(rises) < #(falls); see Comments.

Original entry on oeis.org

12, 24, 25, 36, 37, 38, 48, 49, 50, 51, 60, 61, 62, 63, 64, 72, 73, 74, 75, 76, 77, 84, 85, 86, 87, 88, 89, 90, 96, 97, 98, 99, 100, 101, 102, 103, 108, 109, 110, 111, 112, 113, 114, 115, 116, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 132, 133, 134
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 A296747-A296749 partition the natural numbers. See the guide at A296712.

Examples

			The base-12 digits of 134 are 11,2; here #(rises) = 0 and #(falls) = 2, so 134 is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    z = 200; b = 12; d[n_] := Sign[Differences[IntegerDigits[n, b]]];
    Select[Range [z], Count[d[#], -1] == Count[d[#], 1] &] (* A296747 *)
    Select[Range [z], Count[d[#], -1] < Count[d[#], 1] &]  (* A296748 *)
    Select[Range [z], Count[d[#], -1] > Count[d[#], 1] &]  (* A296749 *)