Where t(n) is the n-th Tribonacci number as defined by: a(0)=1, a(1)=6, a(2)=6, a(n)=a(n-1)+a(n-2)+a(n-3) t(77696)=3379340488 ... 3286919233 t(137975)=2150976862 ... 2549509591 Verified PRP by pfgw.
To be completed...