J. Integer Seq. 13(4), Article ID 10.4.8, 5 p., electronic only (2010)
Summary
Summary: We generalize the concept of happy number as follows. Let $ {\mathbf e}= (e_0,e_1,....)$ be a sequence with $ e_0 = 2$ and $ e_i = \{1,2\}$ for $ i > 0$. Define by
