A sequence defined by a rule from earlier terms is a recurrence. The Fibonacci numbers are the classic: each is the sum of the previous two. Many recurrences have a closed form, for Fibonacci it involves the golden ratio, but computing them term by term is often the clearest path.
Иштөө мисалы · fib(20)
Аткаруу
- F_0 = 0,; F_1 = 1
Each Fibonacci number is the sum of the two before it.
- F_{2} = F_{1} + F_{0} = 1
- F_{3} = F_{2} + F_{1} = 2
- F_{4} = F_{3} + F_{2} = 3
- F_{5} = F_{4} + F_{3} = 5
- F_{6} = F_{5} + F_{4} = 8
- F_{7} = F_{6} + F_{5} = 13
- F_{8} = F_{7} + F_{6} = 21
- \vdots
- F_{19} = F_{18} + F_{17} = 4181
- F_{20} = F_{19} + F_{18} = 6765
Жауап
Эми сиз Задание выберите, нажмите на него или нарисуйте его. Каждый шаг, рисунок, ответ скрыт до тех пор, пока вы не спросите.
Бул жерде колдонулган символдор
Бардык символдорду басып, толук аныктамасын, сүрөтүн жана ар бир тамгасынын маанисин көрсөңүз болот.
Кантип: Sequences
- Each Fibonacci number is the sum of the two before it.
Кээ бирлердин суроосу
Why are primes so important?
Every integer factors into primes in exactly one way, so primes are the atoms of multiplication. Cryptography relies on that factoring being easy to state and hard to do.
How do I tell whether a big number is prime?
Trial division up to the square root works for small numbers. For large ones, probabilistic tests (Miller-Rabin) give an answer that is wrong with negligible probability, and deterministic tests (AKS) exist but are slower.
Кээ бирлери Number Theory
Prime factorisationPrime numbersGCD and LCMModular arithmeticDivisorsNumber basesDiophantine equationsFermat's little theorem and Euler's theoremRSA: cryptography from number theory