A093100 "Lucas-digits": start with "13", append sum of first 2 digits to the preceding number, drop first digit.

13, 34, 47, 711, 118, 182, 829, 2910, 91011, 101110, 11101, 11012, 10122, 1221, 2213, 2134, 1343, 3434, 4347, 3477, 4777, 77711, 771114, 7111414, 1114148, 1141482, 1414822, 4148225, 1482255, 4822555, 82255512, 225551210, 255512104, 555121047

Offset

1,1

Comments

There are only 7 primes in the first 1000 terms of this sequence. The first 6 primes are 13, 47, 829, 2213, 77711, and 174111811681183993. The 7th prime, a(920), has 214 digits. - Harvey P. Dale, Aug 04 2014

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

a(4): sum of first 2 digits of a(3)=11, append 11 to 47 and get 4711, drop first digit and get 711.

Mathematica

ld[n_]:=Module[{idn=IntegerDigits[n]}, FromDigits[Rest[Join[ idn, IntegerDigits[ Total[ Take[idn, 2]]]]]]]; NestList[ld, 13, 40] (* Harvey P. Dale, Aug 04 2014 *)

Crossrefs

Cf. A093086-A093099.

Sequence in context: A164539 A245170 A134864 * A292472 A081271 A190458

Adjacent sequences: A093097 A093098 A093099 * A093101 A093102 A093103

Keyword

nonn,base

Author

Bodo Zinser, Mar 22 2004

Status

approved