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

1,2

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

Links

Table of n, a(n) for n=1..14.

Formula

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

Mathematica

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

Crossrefs

Cf. A000204.

Sequence in context: A262572 A132935 A132930 * A179619 A019519 A243216

Adjacent sequences: A130771 A130772 A130773 * A130775 A130776 A130777

Keyword

base,easy,nonn

Author

Jonathan Vos Post, Aug 19 2007

Status

approved