11 lines
254 B
Plaintext
11 lines
254 B
Plaintext
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Upper-right: (2n-1)²
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Upper-left : (2n-1)² - (2n-2)
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Lower-left : (2n-1)² - 2(2n-2)
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Lower-right: (2n-1)² - 3(2n-2)
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Total (nth spiral): 4(2n-1)² - 6(2n-2)
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Spirals: ceiling(1001/2) = 501
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Sum_{n=2}^{n=501} 16n²-28n+16 = 669 171 000
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Answer = 669171001
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