A130774 Cumulative concatenation of A000204 Lucas numbers (beginning at 1).

1, 13, 134, 1347, 134711, 13471118, 1347111829, 134711182947, 13471118294776, 13471118294776123, 13471118294776123199, 13471118294776123199322, 13471118294776123199322521, 13471118294776123199322521843

Offset: 1

Author

Jonathan Vos Post, Aug 19 2007

Keywords

• base
• easy
• nonn

Comments

a(2) = 13 and a(10) = 13471118294776123 are prime. What is the next prime?

The next prime is a(31), a number of 120 digits. - Giovanni Resta, Jun 18 2016

Crossrefs

Cf. A000204.

Programs

Mathematica

Module[{nn=20,ll},ll=LucasL[Range[nn]];Table[FromDigits[Flatten[IntegerDigits/@Take[ll,n]]],{n,nn}]] (* Harvey P. Dale, May 07 2023 *)

Formula

a(1) = 1; a(n+1) = Concatenate(a(n),A000204(n+1)).