Integral, 9 Bytes

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◙⌡◙▼⌡♦▼e♪

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Integral, 8 Bytes

 ⌡◙▲⌡•▼e

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Explanation

          (space) Push 1
 ⌡◙▲⌡     "◙▲", standing for "duplicate, increment" when evaluated
     •    Swap third-to-top to the top
      ▼   Decrement
       e  Repeat that many times