@puzzlebee,
a(n)=a(n-1)+a(n-2)-d, where d=a(n/3) if 3 divides n, else d=0; 2 initial terms.
And where every third number of the sequence is changed into its alphabetical value: 1, 1,
1, 2, 3,
4, 7, 11,
17, . The sequence ends at 45, since there is no letter in the alphabet with value 71.
1, 1,
A,
2, 3,
D,
7, 11,
Q,
last terms after Q would be 28, 45