a(n+2) = a(n+1) + d
a(n+1) = a(n) + d
a(n+2) = a(n) + 2d
a(n+2) - a(n) = a(19) - a(17) = a(17) - a(15)==a(3) - a(1) = 2d
d = 1
2 + 2² + 2³ + + 2⁹
получили геометрическую прогрессию
b(1) = 2
q = 2
n = 9
S(n) = b1*(q^n - 1)/(q - 1) = 2*(2^9 - 1)/(2 - 1) = 2*(512 - 1)= 2*511 = 1022
a(n+2) = a(n+1) + d
a(n+1) = a(n) + d
a(n+2) = a(n) + 2d
a(n+2) - a(n) = a(19) - a(17) = a(17) - a(15)==a(3) - a(1) = 2d
d = 1
2 + 2² + 2³ + + 2⁹
получили геометрическую прогрессию
b(1) = 2
q = 2
n = 9
S(n) = b1*(q^n - 1)/(q - 1) = 2*(2^9 - 1)/(2 - 1) = 2*(512 - 1)= 2*511 = 1022