We first define the function as a variable, myFirstFun, using the keyword function, which also receives n as argument (no type specification). The latter will exist within the function. We used an integer, but 'n' could also be a vector or a matrix or a string: R handles all this nicely for us.
America in the 20th Century. The 20th century heralded the beginning of a new era in fitness. President Theodore Roosevelt, perhaps the most physically fit president ever to occupy the Oval Office, used his power and own example to encourage U.S. citizens to be physically active.
1 Physical Activity Guidelines for Americans - Types and amounts of physical activity to maintain or improve health.  President's Council on Fitness, Sports and Nutrition - Promote healthy lifestyles through fitness, sports and nutrition programs for every age.