a(n) and Fib(n) are congruent modulo 9 which implies that (a(n) mod 9) is equal to (Fib(n) mod 9) A007887(n). Thus (a(n) mod 9) is periodic with the Pisano period A001175(9)=24. - Hieronymus Fischer (Hieronymus.Fischer(AT)gmx.de), Jun 25 2007
FORMULA
a(n)=Fib(n)-9*sum{k>0, floor(Fib(n)/10^k)}. - Hieronymus Fischer (Hieronymus.Fischer(AT)gmx.de), Jun 25 2007