1 2 1 3 1 2 1 4 1 2 1 3 1 2 1 5 1 2 etc.

[Rainer Rosenthal]

> Oh . . . and J. S. Bach also!!! O

Good old Bach made a hit out of the letters of his name

         B - A - C - H

as you probably know. There should be some musically
experienced SeqFan or MathFan or GaussFan, who composes
some piece on the theme

         C - F - G - A

in honor of good old  C. F. GAuss. 

P.S. I'm still thinking about my R_r and S_r sequences and
compiling the many comments in the related sequences. And
I did find the mentioning of relation  A*C = B^2 - 1 in
a comment of Benoit Cloitre for A001906:

     a(n) = 3*a(n-1) - a(n-2).
     a(0)=0, a(1)=1, a(2)=3, a(n)a(n-2)+1=a(n-1)^2. 
     - Benoit Cloitre, Dec 06 2002

Both remarks are strongly related with Chebyshev's U-function
and it will take me still some time to provide valuable
comments.


Best regards
Rainer Rosenthal
r.rosenthal at web.de