Formula to repeat a value starting at x year and repeating y years

[Robert Davidson]

I am preparing a cashflow model which has a column with years starting at say 2023 going on for several decades. I wish to make a periodic income in the adjacent column that starts in say 2025 then repeats every say 3 years. Could someone help construct a formula for this? The start year, the income, the first income year and the frequency all need to be variables. An example would be. The aim is to produce a periodic income for a NPV calculation arising from felling trees so the frequency could be up to perhaps 120 years.

Year	Income
2023	0
2024	0
2025	1000
2026	0
2027	0
2028	1000
2029	0
2030	0
2031	1000

 

[Peter_SSs]

Dear Peter,
Thank you very much for all your help. Both are helpful but I will stick with the option to continue on the model period while truncating the cashflow early as I will use a series of these formulae for calculating the values of each part of a forest as each one can then be treated differently but the cash flow can be seen to terminate at a common year.
Robert.

OK, so just checking that you are you all sorted now, given that a solution has been marked?

 

[Robert Davidson]

OK, so just checking that you are you all sorted now, given that a solution has been marked?

Yes thank you Peter.

 

[Peter_SSs]

Cheers.