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A074905
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Number of integers with an even number of distinct primes (for which mu(n)=1) between two consecutive primes p(n) and p(n+1).
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0
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0, 0, 1, 1, 0, 2, 0, 2, 1, 0, 3, 2, 0, 1, 1, 3, 0, 2, 1, 0, 2, 1, 3, 4, 0, 0, 1, 0, 1, 5, 1, 2, 0, 5, 0, 1, 3, 1, 0, 2, 0, 3, 0, 1, 0, 7, 7, 1, 0, 0, 2, 0, 2, 2, 2, 2, 0, 1, 1, 0, 2, 7, 1, 0, 1, 7, 2, 3, 0, 0, 2, 2, 1, 1, 2, 1, 5, 1, 2, 4, 0, 2, 0, 1, 0, 3, 3, 1, 1, 1, 4, 3, 1, 2, 2, 1, 6, 0, 6, 4, 3, 2, 2, 1, 1
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,6
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EXAMPLE
| Between 541 and 547 the 4 numbers which have an even number of distinct primes are as follows: {542,543,545,546}, so a(100)=4.
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MAPLE
| readlib(issqr): sstmp := proc(n) local t1, i; t1 := 0; for i from ithprime(n) to ithprime(n+1) do if (issqrfree(i) = 'true' and mobius(i)=1) then t1 := t1+1; fi; od; t1; end: sstmp(200);
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CROSSREFS
| Cf. A061265, A061399.
Sequence in context: A036849 A097364 A177446 * A058548 A157030 A080844
Adjacent sequences: A074902 A074903 A074904 * A074906 A074907 A074908
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KEYWORD
| nonn
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AUTHOR
| Jani Melik (jani_melik(AT)hotmail.com), Sep 30 2002
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