[seqfan] A230044 question

[David Wilson]

It is already conjectured that A064784 has the range A230044.

 

For n >= 0, define

 

                f(n) = 2*t(n) - t(m)

 

Where t(n) = A000217(n) is the nth triangular number, and t(m) is the
largest triangular number <= 2*t(n).

 

This sequence begins

 

f = 0,1,0,2,5,2,6,1,6,12,5,12,3,11,0,9,19,6,17,2,14,...

 

which does not appear to be in the OEIS.

 

I would conjecture that f has the same range A230044.

 

>From playing around with these sorts of numbers, I am inclined to think the
conjectures are true, and provable, but somewhat beyond my capabilities.