Ciągi Paweł: Oblicz: 2a₅ − b₇

	⎧	a1=12
a)	⎨
	⎩	an+1 = (−2)n * an, dla n ≥ 1

⎧	b1=0
⎨
⎩	bn+1 = bn − (−1)n, dla n ≥ 1

Janek191: a₂ = (−2)¹*0,5 = − 1 a₃ = (−2)²* (−1) = − 4 a₄ = (−2)³*(−4) = 32 a₅ = (−2)⁴* 32 = 512 b₂ = 0 − (−1)¹ = 1 b₃ = 1 − (−1)² = 0 b₄ = 0 − (−1)³ = 1 b₅ = 1 − (−1)⁴ = 0 b₆ = 0 − (−1)⁵ = 1 b₇ = 1 − (−1)⁶ = 0 więc 2 a₅ − b₇ = `1024 = 2¹⁰

Adamm:

	1+(−1)n
bn=
	2

	1
an=(−2)n−1*(−2)n−2*...*(−2)*		=(−1)(n−1)+...+1*2(n−1)+...+2=
	2

=(−1)^n(n−1)/2*2^{(n+1)(n−2)/2}