sequence with jump in specific month

[beng986]

hi,

In column B1 I have =sequence(1,36,1,1). This gives the months for 3 years.

In B2 i have some date which starts at 10 and increases by 3. =sequence(1,36,10,3). great.

But every year in month 9 i want to add additional 7 and then resume adding 3. So the first graph shows what I have (adding 3 to every month). The second shows what i want (adding 10 in month 9 then resuming to add 3).

Is there a way of doing this in an array type formula rather than manually dragging an if statement.

Month

1​

2​

3​

4​

5​

6​

7​

8​

9​

10​

11​

12​

Schools

10​

13​

16​

19​

22​

25​

28​

31​

34​

37​

40​

43​

to

Month

1​

2​

3​

4​

5​

6​

7​

8​

9​

10​

11​

12​

Schools

10​

13​

16​

19​

22​

25​

28​

31​

41​

44​

47​

50​

 

[arthurbr]

Perhaps in C2 =B2+3+7*(c1=9) and drag right