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Search: id:A088075
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| A088075 |
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Smallest number sandwiched between two numbers having exactly n prime divisors. |
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+0
2
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| 3, 11, 131, 1429, 77141, 1456729, 117048931, 10326137821, 1110819807371, 140734085123059, 11639258217451019
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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a(n)=m is the smallest number sandwiched between m-1 and m+1 such that both m+1 and m-1 have n distinct prime-factors. No restrictions are imposed for {m-1,m+1} flanker numbers.
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FORMULA
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a(n)=Min{x; A001221[x-1]=A001221[x+1]=n}
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EXAMPLE
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n = 3: a(3) = 131, 130 = 2*5*13 and 132 = 2^2*3*11 both have three prime divisors.
n = 6: a(6) = 1456729 = 103.14143 is between 1456728 = 8.3.7.13.23.29 and 1456730 = 2.5.11.17.19.41.
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CROSSREFS
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Cf. A088076, A088077, A001221.
Sequence in context: A102847 A113258 A113848 this_sequence A088076 A072878 A112957
Adjacent sequences: A088072 A088073 A088074 this_sequence A088076 A088077 A088078
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KEYWORD
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more,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Sep 22 2003
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EXTENSIONS
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Edited by Labos E. (labos(AT)ana.sote.hu), Sep 30 2003
More terms from Ray Chandler (rayjchandler(AT)sbcglobal.net), Oct 07 2003
a(8) and a(9) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Jun 19 2008
a(10)-a(11) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Feb 18 2009
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