Re: [math-fun] Ulam(1,2)

At 09:43 AM 2/11/2003, you wrote:

However based on looking at the first 2000 terms I boldly conjecture that there are only 4 instances where u(n)-u(n-1) = 1.

I tested that up to n=5,000,000 in June 2001, and commented about it in A002858.