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A166305 Even semiprimes n such that the largest prime factor + 8 is a prime. Also semiprimes n such that n+16 is semiprime. 0
6, 10, 22, 46, 58, 106, 118, 142, 178, 202, 262, 298, 346, 382, 466, 526, 538, 718, 778, 802, 862, 898, 958, 982, 1126, 1138, 1186, 1198, 1306, 1366, 1402, 1438, 1486, 1522, 1642, 1822, 1858, 1966, 2026, 2062, 2122, 2218, 2326, 2386, 2446, 2458, 2566, 2578 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..48.

MAPLE

A006530 := proc(n) numtheory[factorset](n) ; max(op(%)) ; end proc: isA166305 := proc(n) if type(n, 'even') then if numtheory[bigomega](n) = 2 then isprime(A006530(n)+8) ; else false; end if; else false; end if; end proc: for n from 4 to 3000 by 2 do if isA166305(n) then printf("%d, ", n) ; end if; end do: [From R. J. Mathar, Jan 30 2010]

MATHEMATICA

Select[2*Range[1500], PrimeOmega[#]==PrimeOmega[#+16]==2&] (* Harvey P. Dale, Dec 28 2013 *)

CROSSREFS

Cf. A108605, A165986.

Sequence in context: A063765 A085712 A179875 * A047651 A079426 A212161

Adjacent sequences:  A166302 A166303 A166304 * A166306 A166307 A166308

KEYWORD

nonn

AUTHOR

Giovanni Teofilatto, Oct 11 2009

EXTENSIONS

Extended by R. J. Mathar, Jan 30 2010

STATUS

approved

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Last modified October 19 09:28 EDT 2018. Contains 316339 sequences. (Running on oeis4.)