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A337611
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Positive integers m such that A126288^k(m) = m for some positive integer k.
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4
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2, 3, 6, 10, 14, 20, 22, 26, 28, 38, 44, 46, 52, 76, 78, 88, 94, 102, 105, 114, 116, 117, 136, 138, 152, 171, 186, 187, 195, 207, 212, 247, 248, 266, 282, 284, 285, 296, 304, 322, 333, 354, 366, 369, 387, 402, 403, 407, 414, 423, 425, 426, 430, 437, 442, 468
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OFFSET
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1,1
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COMMENTS
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Equivalently, the numbers that belong to a cycle under the map x -> A126288(x).
2 and 3 are the only primes in this sequence.
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LINKS
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FORMULA
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EXAMPLE
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PROG
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(PARI) gpf(n) = vecmax(factor(n)[, 1]);
f(n) = if (n==1, 2, n*gpf(n+1)/gpf(n)); \\ A126288
incycle(n, list) = {my(v=Vec(list)); #select(x->(x==n), v); }
cycle(n) = {my(list = List(), repeat=1); while(repeat, n = f(n); if (incycle(n, list), repeat=0); listput(list, n); ); list; }
isok(n) = {my(list = cycle(n)); incycle(n, list); } \\ Michel Marcus, Sep 08 2020
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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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