Interesting problem: A076109

[Ralf Stephan]

> This, i believe, leads to the formula
> 
>     a(n) =
>         0                          if n == 0 (mod 4)
>         A007947(n)/2    if n == 2 (mod 4)
>         A007947(n)       if n == 1 (mod 2)
> 
> The problem is to show that the sequence definition is equivalent to one of 
> these characterizations.

Also, what can be said about A076107?


ralf