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.

A099118 Conjectured number of times that S(k+n) = S(k), where S is the Kempner function A002034.

Original entry on oeis.org

0, 1, 2, 2, 3, 0, 9, 3, 2, 5, 18, 2, 28, 9, 2, 1, 53, 2, 79, 5, 10, 23
Offset: 1

Views

Author

T. D. Noe, Sep 28 2004

Keywords

Comments

Numbers k up to 10^8 have been tested. Tutescu's conjecture is the case n=1.

References

  • L. Tutescu, "On a Conjecture Concerning the Smarandache Function." Abstracts of Papers Presented to the Amer. Math. Soc. 17, 583, 1996.

Crossrefs

Cf. A099119 (greatest k such that S(k) = S(k-n)), A099120 (least m such that n = S(k) = S(k+m)).

Programs

  • Mathematica
    (*See A002034 for the Kempner function*) nMax=22; iMax=10^6; iTab=Table[{}, {nMax}]; cTab=Table[0, {nMax}]; a=Table[Kempner[i], {i, nMax+1}]; Do[If[a[[i]]==a[[i-n]], cTab[[n]]++; AppendTo[iTab[[n]], i]], {n, nMax}, {i, n+1, nMax+1}]; Do[a=RotateLeft[a]; a[[nMax+1]]=Kempner[i]; Do[If[a[[nMax+1]]==a[[nMax-n+1]], cTab[[n]]++; AppendTo[iTab[[n]], i]], {n, nMax}], {i, nMax+2, iMax}]; cTab