A138027 Numbers k where A121561(k) = 4.

1357323, 1357324, 1562041, 1562042, 1671903, 1671904, 1889953, 1889954, 2010855, 2010856, 3826141, 3826142, 3851581, 3851582, 3933721, 3933722, 4652475, 4652476, 4652501, 4738773, 4738774, 5518809, 5518810, 5826123

Offset: 1

Author

Robert G. Wilson v, Feb 27 2008, Mar 06 2008

Keywords

• nonn

Links

• Robert G. Wilson v, Table of n, a(n) for n = 1..100148.

Crossrefs

Cf. A121561, A093515, A093513, A138026.

Programs

Mathematica

LrgstPrm[n_] := Block[{k = n}, While[ !PrimeQ@k, k-- ]; k]; f[n_] := Block[{c = 0, d = n}, While[d > 1, d = d - LrgstPrm@ d; c++ ]; c]; lst = {}; Do[ If[f@n == 4, AppendTo[lst,n]], {n, 2*10^6}]; lst