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A280982
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Partial products of A024816; a(1) = a(2) = 1.
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0
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1, 1, 2, 6, 54, 486, 9720, 204120, 6531840, 241678080, 13050616320, 652530816000, 50244872832000, 4069834699392000, 390704131141632000, 41023933769871360000, 5538231058932633600000, 731046499779107635200000, 124277904962448297984000000
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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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a(1) = a(2) = 1; for n>2, a(n) = Product_{i=3..n} A024816(i).
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MATHEMATICA
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FoldList[#1 #2 &, Table[Boole[n <= 2] + n (n + 1)/2 - DivisorSigma[1, n], {n, 19}]] (* Michael De Vlieger, Jan 11 2017 *)
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PROG
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(Magma) [1, 1] cat [&*[k*(k+1)/2 - SumOfDivisors(k): k in [3..n]]: n in [3..100]]
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CROSSREFS
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Cf. A024816(n) = sum of nondivisors of n.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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