Where t(n) is the n-th Tetranacci number as defined by:
a(0)=0, a(1)=0, a(2)=1, a(3)=0, a(n)=a(n-1)+a(n-2)+a(n-3)+a(n-4)

t(180039)=3046581213 ... 8613511567


Verified PRP by pfgw.

To be completed...