Which of these definitions says about the lack of random patterns?
"Random pattern" is a misnomer, or an oxymoron. You may mean a randomly repeated pattern, or some pattern algorithm with random "mutations", like IadixDev's example with fractals. If it follows a pattern then it's not random.
dictionary.com: "proceeding, made, or occurring without definite aim, reason, or pattern"
Merriam-Webster: "lacking a definite plan, purpose, or pattern"
Cambridge Dictionary: "happening, done, or chosen by chance rather than according to a plan or pattern"