Go on adding 7, 9, 11, 13, 15, 17 respectively to obtain the next number.

Go on dividing by 4 to get the next number.

Let no's be a,b,c,d,e,f,g. then if a=7;  b=a*1+1; c=b*2+2 and so on

Go on multiplying with 1, 2, 3, 4, 5, 6 to get the next number.

Go on subtracting 3 and divide the result by 2 to obtain the next number.

Multiply by 2 and add 1to get the next number.

Go on dividing by 6,5,4,3,2,1 respectively to obtain the next number.

Go on adding 7, 9,11,13,15,17 respectively to obtain the next number.

2^nd term = 1^st term*3 - 4; 3^rd term = 2^nd term*3 - 4 and so on

Multiply the number by 2 and add 1 to it to get the next number.

2 term = 1^st term*1 + 1 ; 3^rd term = 2^nd term*2 + 2  and so on

The numbers must be squares of (14, 13, 12, 11, 10, 9, 8. so 80 is wrong)

2^nd term = 1^st term*1 + sqr of 1; 3^rd term = 2^nd term*2 + sqr of 2 and so on

2^nd term = 1^st term*2 + 2 ; 3^rd term = 2^nd term*2 + 4 ; 4^th term = 3^rd term*2 + 6 and so on

a * 2 + 1, b * 3 + 1, c*2 + 1, d * 3 + 1 and so on

2^nd term = 1^st term + sqr of 2 ; 3^rd term = 2^nd term + sqr of 3 and so on

Subtract 8 from the previous term and divide it by 2 to get the next term

2^nd term = 1st term*2 - 2 ; 3^rd term = 2^nd term*3 - 2 and so on

8^th term*2 + 1 = 7^th term; 7^th term*2 + 2 = 6^th term and so on

2^nd term = 1^st term*1.5 ; 3^rd term = 2^nd term*2 ; 4^th term = 3^rd term*2.5 and so on

2^nd term = ( 1^st term-30)/2 ; 3^rd term = (2^nd term-26)/2 and so on

2^nd term = 1^st term- sqr of 12 ; 3^rd term = 2^nd term - sqr of 10 and so on