OFFSET
1,3
COMMENTS
This is the lexicographically least sequence that fits the rule through 114 digits. There is no guarantee that it can be extended indefinitely. - David Wasserman, Oct 06 2005
EXAMPLE
The first 11 partial concatenations are 1,11,113,1131,11311,113112,1131121,11311211,113112111,1131121112,11311211129.
The 2nd, 3rd, 5th 7th and 11th terms are primes. The rest are composite.
PROG
(PARI) num = 111; n = 3; while (n < 115, isp = isprime(n); while (num%10 && isprime(num) != isp, num++); if (num%10, n++; num = 10*num + 1, num = (num - 1)\10 + 1; n--)); print(digits(num\10)); \\ David Wasserman, Sep 20 2005
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Amarnath Murthy, Nov 22 2003
EXTENSIONS
More terms from David Wasserman, Oct 06 2005
Edited by Charles R Greathouse IV, Apr 29 2010
STATUS
approved