User blog comment:King2218/The Slow Rdc(a, x) Function/@comment-3427444-20140220141144/@comment-10429372-20140220152822

A formal definition:

Rdc(0,n) = 0

Rdc(α+1,n) = Rdc(α,n)+1

Rdc(α,n) = Rdc(α[n],n)+1

Note: Rdc(0,n) = 0 beacause we count the first one.