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Search: id:A120992
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| A120992 |
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Number of integers in n-th run of squarefree positive integers. |
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+0
6
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| 3, 3, 2, 3, 1, 1, 3, 1, 3, 3, 3, 3, 2, 1, 1, 1, 3, 2, 3, 3, 2, 3, 2, 3, 1, 1, 3, 1, 3, 3, 3, 3, 2, 2, 1, 3, 2, 3, 3, 2, 1, 1, 2, 3, 1, 1, 3, 1, 2, 3, 3, 3, 2, 3, 1, 1, 3, 2, 3, 3, 3, 3, 2, 3, 1, 1, 3, 1, 2, 1, 1, 3, 3, 2, 3, 1, 1, 2, 2, 3, 3, 2, 1, 1, 2, 3, 1, 1, 3, 2, 3, 3, 2, 3, 2, 1, 1, 1, 3, 1, 3, 3, 1, 3, 2
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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The values 1, 2 and 3 occur 309008, 251134 and 439858 times, respectively, in the first 1000000 terms. - Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jul 25 2006
1<=a(n)<=3; A136742(n)=PRODUCT(A072284(n)+k:0<=k<a(n)); A136743(n)=SUM(A001221(A072284(n)+k):0<=k<a(n)). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jan 20 2008
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LINKS
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R. Zumkeller, Table of n, a(n) for n = 1..1000
Leroy Quet, Home Page (listed in lieu of email address)
Eric Weisstein's World of Mathematics, Squarefree
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EXAMPLE
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The runs of squarefree integers are as follows:
(1,2,3),(5,6,7),(10,11),(13,14,15),(17),(19),(21,22,23),...
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MAPLE
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with(numtheory): a:=proc(n) if mobius(n)=0 then n else fi end: A:=[0, seq(a(n), n=1..500)]: b:=proc(n) if A[n]-A[n-1]>1 then A[n]-A[n-1]-1 else fi end: seq(b(n), n=2..nops(A)); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Jul 24 2006
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PROGRAM
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(PARI) n=1; while(n<1000, c=0; while(issquarefree(n), n++; c++); print1(c, ", "); while(!issquarefree(n), n++)) - Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jul 25 2006
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CROSSREFS
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Cf. A120993.
Sequence in context: A113780 A007515 A014967 this_sequence A129979 A075017 A060586
Adjacent sequences: A120989 A120990 A120991 this_sequence A120993 A120994 A120995
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet Jul 21 2006
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EXTENSIONS
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More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu) and Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jul 25 2006
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