#Pell Numbers
The Pell numbers/sequence is similar to the Fibonacci sequence, which is when the next number is calculated by adding the two preceding numbers. Pell and Fibonacci sequences both start with 0 and 1, but the difference with the Pell sequence is that it multiplies the second previous number by 2 before adding the first previous term to that calculation.
#Example
The first 10 Pell numbers: 0, 1, 2, 5, 12, 29, 70, 169, 408, 985