3,2

3*2*3*4*5*6*7/(2*3*5*7) -1 = 71 prime twin of 73

3*2*3*4*5*6*7/(2*3*5*7) +1 = 73 prime twin of 71, so k(4)=3 as p(4)=7

Sequence in context: A108931 A032100 A023371 this_sequence A091109 A123982 A113535

Adjacent sequences: A124083 A124084 A124085 this_sequence A124087 A124088 A124089

nonn

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