#Octave, <s>38</s> 37 bytes

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    @(n)[(x=1:n)+x'-1 ~x'+2*n;~[x 1]+2*n]
    
[Try it online!](https://tio.run/##y08uSSxL/f/fQSNPM1qjwtbQKk9Tu0Jd11ChrkJd20grz7ouukLBMBbEjP2fmFesYar5HwA "Octave – Try It Online")

or

    @(n)~(k=blkdiag((x=1:n)+x'-1,0))*2*n+k

[Try it online!](https://tio.run/##y08uSSxL/f/fQSNPs04j2zYpJzslMzFdQ6PC1tAqT1O7Ql3XUMdAU1PLSCtPO/t/Yl6xhqnmfwA "Octave – Try It Online")