Generate Pascal's triangle using purrr

pascal.R

library(tidyverse)
library(stringr)

pascal_triangle <- function(n) {
  df <- data_frame(N = 0:n, k = map(N, seq, from = 0)) %>% 
    unnest() %>% 
    mutate(c = choose(N, k)) %>% 
    group_by(N) %>% 
    summarise(c = paste(c, collapse = "  "))
  
  df$c %>% 
    str_pad(5 * (n + 1), "both") %>% 
    paste(collapse = "\n") %>% 
    cat()
}

pascal_triangle(15)