How to estimate the number of recursive calls

[arira]

So, which small values for N and k did you try?

I wrote a program that gives me the numbes but for (100,50) it takes too long
I am sure that there is a formul

(1,0)=3
(2,0)=5
(2,1)=7
(3,0)=7
(3,1)=13
(3,2)=15
(4,0)=9
(4,1)=21
(4,2)=29
(4,3)=31
(5,0)=11
(5,1)=31
(5,2)=51
(5,3)=61
(5,4)=63
(6,0)=13
(6,1)=43
(6,2)=83
(6,3)=113
(6,4)=125
(6,5)=127
(7,0)=15
(7,1)=57
(7,2)=127
(7,3)=197
(7,4)=239
(7,5)=253
(7,6)=255
(8,0)=17
(8,1)=73
(8,2)=185
(8,3)=325
(8,4)=437
(8,5)=493
(8,6)=509
(8,7)=511