A103992 Palindromic primes: insert a digit between digits of the previous term.

11, 101, 16061, 126202621, 13236323032363231

Offset

1,1

Comments

Inserted digits are 0, 6, 2, 3. If we search only for minimal inserted digit and start with 11, the sequence ends at 5th term. - Ray Chandler, Feb 25 2005

Links

Table of n, a(n) for n=1..5.

Example

Start with 11; insert 0 between digits, 101 is prime; insert 6 between digits, 16061 is prime, etc.

Mathematica

nxt[n_]:=SelectFirst[FromDigits/@Table[Riffle[IntegerDigits[n], i], {i, 0, 9}], PrimeQ]; NestList[nxt, 11, 4] (* The program uses the SelectFirst function from Mathematica version 10 *) (* Harvey P. Dale, Aug 08 2015 *)

Crossrefs

Sequence in context: A082620 A199304 A156668 * A185949 A001387 A358198

Adjacent sequences: A103989 A103990 A103991 * A103993 A103994 A103995

Keyword

fini,nonn,base

Author

Zak Seidov, Feb 23 2005

Extensions

Corrected by Ray Chandler, Feb 25 2005

Status

approved