1,4,9,16,25,36,49,64,81,100,121,144,169,196,225,256,289,324,361,400 All the square numbers up to 20!
1,3,6,10,15,21,28,36,45,47,66,78,91,95
45
1, 3, 6, 10, 15, 21, 28, 36
There are exactly 200 of them.
1,4,9,16,25,36,49,64,81,100,121,144,169,196,225,256,289,324,361,400 All the square numbers up to 20!
1,3,6,10,15,21,28,36,45,47,66,78,91,95
45
1'3'10 etc;
1, 3, 6, 10, 15, 21, 28, 36
Just count up all the even numbers which will all be divisible by 2
Numbers up to 200 divisible by both 2 and 3 = numbers to 200 divisible by 2*3 = 6 which is int(200/6) = int(33.33) = 33
There are exactly 200 of them.
28 and 10 are both triangular numbers and add up to 38
There are 45 prime numbers that are less than 200 (including '1'.)
There are 44 of them. Use the formula T(n) = n*(n+1)/2 to find the nth one.
1, 3, 6, 10, 15, 21, 28, 36, 45, 55, 66, 78 and 91.