1,1

2*2-1=3, 3 prime so a(1)=2

2*2*3-1=11, 11 prime so a(2)=3

2*2*3*5-1=59, 59 prime so a(3)=5

Cf. A119834 A119835.

Sequence in context: A061248 A059498 A158085 this_sequence A127049 A142885 A108547

Adjacent sequences: A119830 A119831 A119832 this_sequence A119834 A119835 A119836

nonn

Pierre CAMI (pierrecami(AT)tele2.fr), May 25 2006