The Lucas numbers

Rule

Each term is: Take the sum of the previous two terms

Known as: The Lucas numbers

Similar to the Fibonacci sequence, but starting with 2, 1.

The first 50 terms (starting from n=1) are:

2 1 3 4 7 11 18 29 47 76 123 199 322 521 843 1364 2207 3571 5778 9349 15127 24476 39603 64079 103682 167761 271443 439204 710647 1149851 1860498 3010349 4870847 7881196 12752043 20633239 33385282 54018521 87403803 141422324 228826127 370248451 599074578 969323029 1568397607 2537720636 4106118243 6643838879 10749957122 17393796001

Example

To get the value for n=13:

• Add my previous answer to the number.

For example, if my previous answer was 10 this gives 23.

So the result is 23.