Question

Tentukan :

a10
a20
a26
a50
a100
a1000

Answer 1

(x,y) --> (2,2),(4,4),(7,7),(11,11_
..(2,4,7,11)
.....2..3..4
.......1...1
a= 2, b = 2 , c = 1

an = a +(n-1)b + 1/2 (n-1)(n-2)
an = 1/2 (n² + n + 2)
a10 = 1/2 (100+10 +2) = 56 --> (x,y) = (56,56)
a20 --> (x,y) = (211, 211)
a26 --> (x,.y) = (352, 353)
a50--> (x,y) = (1276, 1276)
a100 --> (x,y) =(5051, 5051)
a1000--> (x,y) = (500501, 500501)