## 3 treatments with two-at-a-time approach [Power / Sample Size]

Dear all,
First, thank you to the authors of PowerTOST and the maintainers of this wonderful forum.

I have a question about how the sample size is calculated for 1 test (A) and 2 references (B and C) based on 3x6x3 design. I am interested in showing the BE based on both A/C and B/C. If I were to use the two-at-a-time analysis approach, can I use the following function to get the sample size?

sampleN.TOST(CV = 0.2, design = "2x2") Sample size (total)  n     power 20   0.834680  

Based on this output, I am to assign 20/6 ~ 4 participants in each of the 6 sequences. I am hoping my reasoning is correct

Also, I was unable to find any reference for the sample size calculation and wondered if anyone can kindly point me to the right direction.

Thank you!