OFFSET
1,1
COMMENTS
a(5) = 3*10^333-1 = 2999...999 with 333 9's and contains 334 digits.
Surprisingly enough the first four terms are all primes and match those of A062802, but a(5) is divisible by 65033 and is different from A062802(5).
Sequences with other seeds: 3,12,129,399999999999999,...; 4,13,139,4999999999999999,...; 5,14,149,59999999999999999.
FORMULA
For n>=3, a(n) = (a(n-1) mod 9 + 1)*10^floor(a(n-1)/9) - 1. - Max Alekseyev, Aug 13 2015
For n>=3, a(n) = 3*10^b(n) - 1, where b(3)=1 and for n>=4, b(n)=(10^b(n-1)-1)/3. In other words, decimal representation of b(n) is formed by digit 3 repeated b(n-1) times. - Max Alekseyev, Aug 13 2015
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Zak Seidov, Feb 17 2005
STATUS
approved