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A088949
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Composite numbers k such that (A006530(k) + A020639(k))/2 is an integer that divides k; special terms of A088948.
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2
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4, 8, 9, 16, 25, 27, 32, 49, 64, 81, 105, 121, 125, 128, 169, 231, 243, 256, 289, 315, 343, 361, 512, 525, 529, 625, 627, 693, 729, 735, 841, 897, 935, 945, 961, 1024, 1155, 1331, 1369, 1575, 1581, 1617, 1681, 1729, 1849, 1881, 2048, 2079, 2187, 2197, 2205, 2209
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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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k = 315 = 3*3*5*7 (composite); (3 + 7)/2 = 5, which divides k.
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PROG
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(PARI) lista(nn) = {forcomposite(n=1, nn, my(f = factor(n)[, 1], x = (vecmin(f) + vecmax(f))/2); if ((denominator(x)==1) && !(n % x), print1(n, ", ")); ); } \\ Michel Marcus, Jul 09 2018
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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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