Archipelago consists of n islands : I1,I2,...,In and a1,a2,...,an - number of the roads on each island. a_1 \equal{} 55, a_k \equal{} a_{k \minus{} 1} \plus{} (k \minus{} 1), ( k \equal{} 2,3,...,n)
a) Does there exist an island with 2008 roads?
b) Calculate a_1 \plus{} a_2 \plus{} ... \plus{} a_n. inductionalgebra proposedalgebra