'In R or excel, can I add a column of x amount of each number counting up

Basically I have a dataset extracted from photos. Each photo has 25 data points but there is no indication which photo each point is from. I would like to add a column where I have 25 x 1's, 25 x 2's, 25 x 3's etc for around 2500 photos so I can distinguish individual images. Any suggestions? TIA

Example of table



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