Patterns & Sequences

Save $4 more every week and your balance climbs 4, 8, 12, 16… a staircase with even steps. Double a bacterium every hour and you get 1, 2, 4, 8, 16… a snowball that explodes. Both are sequences — ordered lists with a rule. The staircase adds a constant; the snowball multiplies one. These two patterns, arithmetic and geometric, are the seeds of every line and every exponential you've graphed.