sampleSizeOne: samplesizeone calculates the sample size for a one treatment...
In Gtmille2/twoStageSeamless: What the Package Does (One Line, Title Case)

This function is used to calculate the sample size for a one treatment case

1 2	sampleSizeOne(z.alpha, z.beta, rho, beta1, beta0, sigma, tau, mu.delta, gam = NULL)

`z.alpha`	z alpha is the set Type I error level
`z.beta`	Z beta is the set power level
`rho`	Is the allocation ratio of available long-term endpoints to short-term endpoints
`beta1`	Beta1 is the beta from the relationship between the X and Y variable
`beta0`	Beta 0 is the beta from the relationship between the X and Y variable
`sigma`	Sigma is either one sigma or two sigmas if two treatments
`tau`	Tau is used in the calculation of r
`mu.delta`	Mu.delta is the set level between the treatment and control, or the two treatments
`gam`	Gamma is the ratio between the two treatment groups and is not used in this case