A124290 Largest prime < 10*a(n-1), a(1)=11.

11, 109, 1087, 10867, 108649, 1086469, 10864669, 108646667, 1086466657, 10864666531, 108646665307, 1086466653067, 10864666530661, 108646665306581, 1086466653065803, 10864666530658001, 108646665306579997, 1086466653065799961, 10864666530657999467, 108646665306579994669

Offset: 1

Author

Artur Jasinski, Dec 16 2006

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A124262.

Programs

Mathematica

NestList[NextPrime[10#,-1]&,11,20]  (* Harvey P. Dale, Mar 09 2011 *)