1,1

1*13*(1*13-1)-1=155 composite

2*13*(2*13-1)-1=649 composite

3*13*(3*13-1)-1=1481 prime so k(1)=3 P(1)=1481

Cf. A141233 A141234 A141236 A141237 A141238 A141239 A141240.

Sequence in context: A142705 A072346 A103236 this_sequence A051917 A133932 A111999

Adjacent sequences: A141232 A141233 A141234 this_sequence A141236 A141237 A141238

nonn

Pierre CAMI (pierrecami(AT)tele2.fr), Jun 16 2008