Is gta online a sequel to san andreas?

The available information confirms that Grand Theft Auto: San Andreas was released in 2004 as the fifth main entry in the Grand Theft Auto series. It follows the story of Carl "CJ" Johnson in the fictional state of San Andreas. No source in the evidence discusses GTA Online or its relationship to this title. Therefore, based solely on the provided facts, we cannot state that GTA Online is a sequel to San Andreas. Additional sources would be required to confirm any direct narrative or gameplay connection between the two.