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.

A297133 Numbers whose base-5 digits d(m), d(m-1),..., d(0) have m=0 or else d(i) = d(i+1) for some i in {0,1,...,m-1}.

Original entry on oeis.org

1, 2, 3, 4, 6, 12, 18, 24, 25, 30, 31, 32, 33, 34, 37, 43, 49, 50, 56, 60, 61, 62, 63, 64, 68, 74, 75, 81, 87, 90, 91, 92, 93, 94, 99, 100, 106, 112, 118, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 131, 137, 143, 149, 150, 151, 152, 153, 154, 155, 156
Offset: 1

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Author

Clark Kimberling, Jan 14 2018

Keywords

Comments

These numbers comprise the complement of the set of numbers in the union of A297131 and A297132.

Examples

			Base-5 digits of 5000: 1,3,0,0,0,0, so that 5000is in the sequence.
		

Crossrefs

Programs

  • Mathematica
    a[n_, b_] := Sign[Differences[IntegerDigits[n, b]]]; z = 300;
    b = 5; t = Table[a[n, b], {n, 1, 10*z}];
    u = Select[Range[z], ! MemberQ[t[[#]], 0] && First[t[[#]]] == 1 &]   (* A297131 *)
    v = Select[Range[z], ! MemberQ[t[[#]], 0] && First[t[[#]]] == -1 &]  (* A297132 *)
    Complement[Range[z], Union[u, v]]  (* A297133 *)