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A128972
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n^3 - 1 divided by its largest cube divisor.
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1
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7, 26, 63, 124, 215, 342, 511, 91, 37, 1330, 1727, 2196, 2743, 3374, 4095, 614, 17, 254, 7999, 9260, 10647, 12166, 13823, 1953, 17575, 19682, 813, 24388, 26999, 29790, 32767, 4492, 39303, 42874, 46655, 1876, 54871, 59318, 63999, 8615, 74087, 79506
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OFFSET
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2,1
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COMMENTS
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In other words, cubefree part of n^3-1, or cube-free kernel of n^3-1. Cube analogue of A068310.
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LINKS
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Table of n, a(n) for n=2..43.
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FORMULA
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a(n) = A062378(A068601(n)) = A062378(n^3-1).
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EXAMPLE
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a(9) = (9^3-1)/8 = (2^3 * 7 * 13)/(2^3) = 728/8 = 91.
a(10) = (10^3-1)/27 = (3^3 * 37)/(3^3) = 999/27 = 37.
a(18) = (18^3-1)/343 = (7^3 * 17)/(7^3) = 5831/343 = 17.
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CROSSREFS
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Cf. A002350, A004709, A007948, A062378, A067872, A033314, A068310.
Sequence in context: A211645 A171340 A046433 * A135300 A024001 A068601
Adjacent sequences: A128969 A128970 A128971 * A128973 A128974 A128975
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KEYWORD
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easy,nonn
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AUTHOR
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Jonathan Vos Post, Apr 28 2007
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EXTENSIONS
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More terms from Carl R. White, Nov 09 2010
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STATUS
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approved
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