A294952 Triangle read by rows: T(n,k) is the number of n-digit numbers having a k-digit greatest prime factor.

9, 36, 54, 95, 470, 335, 197, 2854, 3547, 2402, 356, 13370, 31999, 25577, 18698, 579, 54250, 236147, 256465, 199403, 153156, 882, 196729, 1486448, 2386859, 1999848, 1633601, 1295633, 1272, 653419, 8615121, 19298617, 19999102, 16384481, 13828384, 11219604

Offset: 1

Author

Jon E. Schoenfield, Nov 11 2017

Keywords

• nonn
• base
• tabl

Comments

By convention, gpf(1) = 1; see A006530.

Examples

			Table begins
     9;
    36,     54;
    95,    470,     335;
   197,   2854,    3547,     2402;
   356,  13370,   31999,    25577,    18698;
   579,  54250,  236147,   256465,   199403,  153156;
   882, 196729, 1486448,  2386859,  1999848,  1633601,  1295633;
  1272, 653419, 8615121, 19298617, 19999102, 16384481, 13828384, 11219604;
		

Links

• Charles R Greathouse IV, Table of n, a(n) for n = 1..66

Crossrefs

Cf. A006530.

First column gives A085630.

Programs

PARI

row(n)=if(n<2, return([9])); my(v=vector(n)); forfactored(k=10^(n-1),10^n-1, v[#Str(vecmax(k[2][,1]))]++); v \\ Charles R Greathouse IV, Nov 12 2017