1,1

1^2+3*1+1=5 prime so a(1)=5

2^2+3*2+1=11 prime so a(2)=11

6^2+3*6+1=55 =5*11 composite so a(6)=0

Sequence in context: A038872 A141158 A130828 this_sequence A088059 A165900 A028387

Adjacent sequences: A108148 A108149 A108150 this_sequence A108152 A108153 A108154

nonn

Pierre CAMI (pierrecami(AT)tele2.fr), Jun 06 2005