(38G) OEIS A262389: Last Digit Composite

[Gerald H]

The 3 recursions can be telescoped into one, producing a faster method of generating the series.

Code:

RECURSE(U,IFTE(N>5,U1(N-1)+U1(N-4)-U1(N-5),IFTE(N==5,14,IFTE(N==4,9,8))),4,6)►U1(N):
CHECK 1:

Although I find the first version more pretty.