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A351926
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a(n) = Sum_{d|n, p|n, (p^d)|n, p prime} p.
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0
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0, 2, 3, 4, 5, 5, 7, 4, 3, 7, 11, 7, 13, 9, 8, 6, 17, 8, 19, 9, 10, 13, 23, 9, 5, 15, 6, 11, 29, 10, 31, 6, 14, 19, 12, 10, 37, 21, 16, 9, 41, 12, 43, 15, 8, 25, 47, 11, 7, 12, 20, 17, 53, 11, 16, 11, 22, 31, 59, 12, 61, 33, 10, 6, 18, 16, 67, 21, 26, 14, 71, 12, 73, 39, 8, 23, 18
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OFFSET
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1,2
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LINKS
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EXAMPLE
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a(12) = 7; we have 2^1, 2^2 and 3^1 dividing 12, so a(12) = 2 + 2 + 3 = 7.
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PROG
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(PARI) a(n) = my(f=factor(n), d=divisors(f)); sum(k=1, #f~, sum(m=1, #d, if ((n % f[k, 1]^d[m]) == 0, f[k, 1]))); \\ Michel Marcus, Feb 26 2022
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CROSSREFS
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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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