[eesmith]

Thanks!

I wish I could find a published list of that table of 15 values.

In my search, I found https://www.jstor.org/stable/2002889?Search=yes&resultItemCl... which comments that an optimum interval table of sines and cosines for 7 place values has 2700 cards instead of 9000. "Each time this table is used, more than two hours of sorting and gang punching time is saved."

The only published "optimum interval table" I could find in archive.org was https://archive.org/details/dli.ernet.212891/page/149/mode/2... where table VII is the function f(r*2) = 1/r*3.

> This is the first time that such a table has ever been printed for use with a hand calculating machine. However, the computer will find that it is easier to use than an ordinary table which requires second difference interpolation, since no interpolating coefficients are needed; and it is not necessary to pay any attention to the irregular intervals.

One of the worked out examples is:

  r^2 = 4.043172
  F = (0.04686041 - 0.043172 x 0.01420874 ) x (-0.043172) + 0.124999851 
    = 0.12300327