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A133133
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a(n) is the largest prime factor of the sum of the largest prime factors of numbers from 2 to n.
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1
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2, 5, 7, 3, 5, 11, 3, 3, 2, 43, 23, 59, 11, 71, 73, 5, 31, 7, 13, 31, 5, 79, 23, 83, 179, 13, 7, 109, 223, 127, 2, 89, 71, 97, 7, 331, 7, 11, 23, 409, 13, 17, 47, 19, 83, 109, 137, 37, 7, 577, 59, 643, 19, 73, 83, 683, 89, 257, 97, 31, 31, 7, 877, 89, 53, 11, 197, 7, 29, 181, 11
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OFFSET
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2,1
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LINKS
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EXAMPLE
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a(11) = gpf(43) = 43;
a(12) = gpf(46) = 23.
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MAPLE
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gpf:= proc(n) max(numtheory:-factorset(n)) end proc:
map(gpf, ListTools:-PartialSums(map(gpf, [$2..100])));
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PROG
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(PARI) gpf(n) = vecmax(factor(n)[, 1]);
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CROSSREFS
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KEYWORD
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AUTHOR
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Paul Finley (pfinley(AT)touro.edu), Sep 21 2007
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STATUS
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approved
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