A241182 - OEIS

%I #21 Jul 26 2020 07:41:26

%S 1,5,3,2,22,19,4020,4280,22198,22194,22193,31400,221101,360648,370260,

%T 604062,604060,1357201,2010734,2010733,4652353,4652352,17051708,

%U 17051707,20831329,20831323,47326699,47326692,123346277,256526120,428045488,436273045,436273038

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

%C The analogous sequence corresponding to A241181 is A336382. - _Rémy Sigrist_, Jul 25 2020

%H Rémy Sigrist, <a href="/A241182/a241182.txt">C# program for A241182</a>

%t A241180[n_] := Module[{c, nx},

%t    c = 1; nx = n;

%t    While[ !

%t      AnyTrue[nx = Union[Flatten[nx + IntegerDigits[nx]]],

%t       PrimeQ [#] && # > n &], c++];

%t    Return[c]];

%t A241182[n_] := Module[{i = 1},

%t    While[A241180[i] != n, i++];

%t    Return[i]];

%t Table[A241182[i], {i, 8}] (* _Robert Price_, Mar 18 2019 *)

%o (C#) See Links section.

%Y Related sequences: A241173, A241174, A241175, A241176, A241177, A241178, A241179, A241180, A241181, A241182, A241183, A336382.

%K nonn,base

%O 1,2

%A _N. J. A. Sloane_, Apr 23 2014

%E a(5) corrected and a(6)-a(30) added by _Hiroaki Yamanouchi_, Sep 05 2014

%E More terms from _Rémy Sigrist_, Jul 26 2020