1,1

R. J. Mathar did an exhaustive search up to 74000000. Kohmoto found one more term. 2^8*3*11*43*257*509 But between 7.4*10^7 and it, many terms be missing.

Cf. A123182.

Sequence in context: A159494 A104003 A015103 this_sequence A074656 A135397 A042421

Adjacent sequences: A123178 A123179 A123180 this_sequence A123182 A123183 A123184

nonn

Yasutoshi Kohmoto zbi74583(AT)boat.zero.ad.jp,Oct 03 2006