If you want to automate the download of files which have a slight variation in their filenames when using a shell such as zsh or bash, do the following:

Examples

Download files with curl:

for i in {1..10}; do curl -O https://www.somesite.com/files/lecture_$i.md; done

Download files with wget:

for i in {1..10}; do wget https://www.somesite.com/files/lecture_$i.md; done

Download files with aria2c:

aria2c -i <(for i in {1..10}; do echo https://www.somesite.com/files/lecture_$i.md; done)

Parallel downloading

aria2c -i <(for i in {1..10}; do echo https://www.somesite.com/mp3/lecture_$i.md; done) -j 4