This is the fibonacci sequence
The next term is the sum of the previous 2 terms.
1+1 = 2
1+2 = 3
2+3 = 5
and so on
This sequence is defined implicitly. List the first six terms of this sequence?
d0 = 1 = d1 and dn+2 = dn+1 + dn.
The 0 in d0 is lower to the d and the 1 in d1 is lower to the d, and the n+2 and n+1 next to the d's are lower and the last dn has the n lower (I hope you get my drift!)