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A132996
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a(n) = gcd(Sum_{k=1..n} c(k), Product_{j=1..n} c(j)), where c(k) is the k-th composite.
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0
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4, 2, 6, 27, 1, 1, 63, 6, 2, 112, 12, 9, 175, 1, 224, 250, 1, 5, 5, 1, 400, 14, 7, 5, 3, 6, 2, 8, 12, 3, 17, 847, 896, 22, 1, 1, 1, 6, 2, 1, 3, 3, 1, 2, 6, 31, 1, 1, 26, 4, 28, 2, 1, 1, 10, 2368, 2448, 9, 7, 2695, 20, 2, 1, 1, 31, 18, 2, 1, 9, 3596, 52, 10, 1, 1, 1, 5, 4300, 2, 74, 4624
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OFFSET
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1,1
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LINKS
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EXAMPLE
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The first 8 composites are 4,6,8,9,10,12,14,15. 4+6+8+9+10+12+14+15 = 78 = 2*3*13. So a(8) = gcd(2*3*13, 4*6*8*9*10*12*14*15) = 6.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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