1,9,7,17,33,57,107,197****
Starting with 4th term, each term is the sum of the 3 previous terms.
1st 3 terms: a=1, b=9, c=7
100a + 10b + c = 197****
So 8th term is the first 3 terms "stuck together"!
a,b,c being digits from 1 to 9, there is another similar sequence;
this one has 11 terms: can you find it?