An 11t17p and 39t17p gear.
Chevron style, so self centering.
Mesh well - less noise - no slack.
45 degree angle on base (and top) so layer zero is just a circle, so easy to print.
P.S. 11t is 11 teeth, and 17p is 17 teeth per inch diameter, so 17 per inch*pi circular pitch is 4.693mm or on inkscape gear plugin 16.63 pixels circular pitch.