Divide 1 to 77 into 20 scales

Divide the numbers from 1-77 into 20 scales, with each scale representing the following numerical intervals:

Size 1st: 1 - 4

Size 2nd: 5 - 8

Size 3rd: 9 - 12

Size 4th: 13 - 16

Size 5th: 17 - 20

Size 6th: 21 - 24

Size 7th: 25 - 28

Size 8th: 29 - 32

Size 9th: 33 - 36

Size 10th: 37 - 40

Size 11th: 41 - 44

Size 12th: 45 - 48

Size 13th: 49 - 52

Size 14th: 53 - 56

Size 15th: 57 - 60

Size 16th: 61 - 64

Size 17th: 65 - 68

Size 18th: 69 - 71

Size 19th: 72 - 74

Size 20th: 75 - 77