Modified the calculation of alfa, R, and a slight change with the for loop
clear;
r=1; % small circles radius
n=17; %number of small crircles
alfa=180-(180*(n-2))/n; %angle
x0=0;y0=0;%circle center points
R=r*(1/(sind(180/n)) -1); %calculating the R(radius of red inner circle)
%innercircle coords
t=0:360;
xymp=x0+R.*cosd(t);
yymp=y0+R.*sind(t);
%outer circle coords
t=0:360;
Syy=+(R+(r.*2))*cosd(t);
Syx=y0+(R+(r.*2))*sind(t);
plot(xymp,yymp,'r','linewidth',2)%inner circle
hold on
plot(Syx,Syy,'b','linewidth',2) %outer circle
s=0:alfa:360;
for k=1:n
x=x0+(R+r).*cosd(s(k));
y=y0+(R+r).*sind(s(k));
xy=x+r.*cosd(t);
yy=y+r.*sind(t);
plot(xy,yy,'-k')
end
hold off
