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.

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A241182 Smallest number requiring n steps to reach a prime under the "add a digit" process described in A241180.

Original entry on oeis.org

1, 5, 3, 2, 22, 19, 4020, 4280, 22198, 22194, 22193, 31400, 221101, 360648, 370260, 604062, 604060, 1357201, 2010734, 2010733, 4652353, 4652352, 17051708, 17051707, 20831329, 20831323, 47326699, 47326692, 123346277, 256526120, 428045488, 436273045, 436273038
Offset: 1

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Author

N. J. A. Sloane, Apr 23 2014

Keywords

Comments

The analogous sequence corresponding to A241181 is A336382. - Rémy Sigrist, Jul 25 2020

Crossrefs

Programs

  • Mathematica
    A241180[n_] := Module[{c, nx},
       c = 1; nx = n;
       While[ !
         AnyTrue[nx = Union[Flatten[nx + IntegerDigits[nx]]],
          PrimeQ [#] && # > n &], c++];
       Return[c]];
    A241182[n_] := Module[{i = 1},
       While[A241180[i] != n, i++];
       Return[i]];
    Table[A241182[i], {i, 8}] (* Robert Price, Mar 18 2019 *)

Extensions

a(5) corrected and a(6)-a(30) added by Hiroaki Yamanouchi, Sep 05 2014
More terms from Rémy Sigrist, Jul 26 2020
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