A sequence a1,a2,a3,…a_1, a_2, a_3, \dotsa1,a2,a3,… is defined by
an+1=6−an a_{n+1} = 6 - a_nan+1=6−anwhere a1=2a_1 = 2a1=2.
Find the value of
(i) a2a_2a2
(ii) a85a_{85}a85
∑n=1100(3an+2)\sum_{n=1}^{100} (3a_n + 2)∑n=1100(3an+2)
308 exam-style questions on OCR A Level Maths 1.4 Sequences and Series, covering 1.4.1 Binomial expansion for positive integer n, 1.4.2 Link to binomial probabilities, 1.4.3 Binomial expansion for rational n (A-level only), 1.4.4 Validity of the expansion (A-level only), 1.4.5 Sequences (A-level only), 1.4.6 Increasing, decreasing and periodic sequences (A-level only), 1.4.7 Sigma notation (A-level only), 1.4.8 Arithmetic sequences and series (A-level only), 1.4.9 Geometric sequences and series (A-level only), 1.4.10 Sum to infinity of a geometric series (A-level only), and 1.4.11 Modelling with sequences and series (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.