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A274401
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Number of balanced linear 4-partitions of the n X n grid.
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1
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0, 1, 8, 3, 16, 7, 32, 13, 48, 19, 80, 29, 96, 41, 144, 49, 176, 65, 224, 83, 256, 95, 336, 117, 368, 137, 464, 155, 512, 183, 576, 213, 640, 233, 768, 257, 816, 293, 960, 317, 1024, 357, 1120, 399, 1200, 423, 1376, 469, 1440
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OFFSET
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1,3
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LINKS
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FORMULA
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For odd n, a(n) = 8 * A002088((n-1)/2).
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PROG
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(PARI) { a(n) = if(n%2, 8*sum(m=1, (n-1)\2, eulerphi(m)), sum(m=0, (n-1)\2, eulerphi(2*m+1)) ); }
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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