Youtube channels/series

• 3Blue1Brown
• Stand-up Maths
• PBS Infinite Series (discontinued)
• MindYourDecisions
• Michael Penn
• Havard Statistics 110: Probability
• Numberphile
• Mathologer
• Mathemaniac
• Blackpenredpen
• Flammable Maths
• MIT OpenCourseWare Math courses

Podcasts

• The Joy of X
• The 3B1B Podcast
• Numberphile Podcast

Encyclopedia/Wikis

• Wolfram Mathworld