10 What is the Pell-Lucas Sequence?

A002203 – OEIS

The Pell-Lucas sequence is calculated recursively by

or as a closed formula

The first numbers are
2,
2,
6,
14,
34,
82,
198,
478,
1154,
2786,
6726,
16238,
39202,
94642,
228486,
551614,
1331714,
3215042,
7761798,
18738638,
45239074,
109216786,
263672646,
636562078,
1536796802,
3710155682,
8957108166,
21624372014,
52205852194,
126036076402,
304278004998