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Search: id:A115166
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| A115166 |
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Even numbers n such that n-2 and n+2 have the same number of distinct prime divisors. |
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+0
1
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| 6, 8, 12, 16, 20, 22, 24, 26, 36, 38, 42, 46, 48, 50, 52, 54, 56, 60, 68, 70, 74, 78, 84, 90, 94, 96, 98, 102, 106, 110, 112, 114, 120, 128, 144, 146, 150, 152, 160, 162, 164, 172, 174, 184, 186, 188, 190, 194, 198, 204, 210, 214, 216, 232, 234, 236, 246, 252, 262
(list; graph; listen)
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OFFSET
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4,1
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EXAMPLE
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38 is in the sequence because 36=2^2*3^2 and 40=2^3*5.
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MAPLE
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with(numtheory): a:=proc(n) if nops(factorset(n-2))=nops(factorset(n+2)) then n else fi end: seq(a(2*n), n=2..133); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Mar 12 2006
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PROGRAM
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(PARI) g(n) = forstep(x=4, n, 2, p1=omega(x-2); p2=omega(x+2); if(p1==p2, print(x", ")))
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CROSSREFS
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Adjacent sequences: A115163 A115164 A115165 this_sequence A115167 A115168 A115169
Sequence in context: A096175 A027827 A059611 this_sequence A050992 A090259 A089241
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KEYWORD
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easy,nonn
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AUTHOR
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Cino Hilliard (hillcino368(AT)gmail.com), Mar 03 2006
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