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A090325 Least (distinct) k such that k, k+n, k+2n are all composite. Rearrangement of composite numbers. 1
8, 4, 6, 10, 15, 9, 14, 12, 16, 18, 22, 20, 25, 21, 24, 26, 28, 27, 30, 32, 33, 34, 35, 36, 38, 39, 42, 40, 46, 44, 49, 48, 45, 50, 51, 52, 54, 56, 55, 58, 63, 57, 62, 60, 65, 64, 68, 66, 70, 69, 72, 74, 76, 75, 77, 78, 81, 80, 82, 84, 85, 86, 87, 88, 90, 92, 91, 94, 93, 95, 98 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

MAPLE

N:= 100: # to get all terms before the first term > N

Avail:= remove(isprime, [$4..N]):

for n from 1 while Avail <> [] do

  for a in Avail while isprime(a+n) or isprime(a+2*n) do od:

  if a = Avail[-1] and isprime(a+n) or isprime(a+2*n) then break fi;

  A[n]:= a;

  Avail:= subs(a=NULL, Avail);

od:

seq(A[i], i=1..n-1); # Robert Israel, Nov 19 2017

CROSSREFS

Sequence in context: A266556 A199434 A253073 * A090469 A322743 A168546

Adjacent sequences:  A090322 A090323 A090324 * A090326 A090327 A090328

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Dec 02 2003

EXTENSIONS

More terms from David Wasserman, Nov 04 2005

STATUS

approved

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Last modified May 21 15:27 EDT 2019. Contains 323444 sequences. (Running on oeis4.)