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 A046930 Size of sea of composite numbers surrounding n-th prime. 5
 1, 1, 2, 4, 4, 4, 4, 4, 8, 6, 6, 8, 4, 4, 8, 10, 6, 6, 8, 4, 6, 8, 8, 12, 10, 4, 4, 4, 4, 16, 16, 8, 6, 10, 10, 6, 10, 8, 8, 10, 6, 10, 10, 4, 4, 12, 22, 14, 4, 4, 8, 6, 10, 14, 10, 10, 6, 6, 8, 4, 10, 22, 16, 4, 4, 16, 18, 14, 10, 4, 8, 12, 12, 10, 8, 8, 12, 10, 10, 16, 10, 10, 10, 6, 8, 8 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 LINKS T. D. Noe, Table of n, a(n) for n=1..10000 FORMULA a(n) = A031131(n) - 2 for n > 1. - Reinhard Zumkeller, Dec 19 2013 EXAMPLE 23 is in a sea of 8 composites: 20,21,22,23,24,25,26,27,28. MAPLE [ seq(ithprime(i)-ithprime(i-2)-2, i=3..100) ]; MATHEMATICA Table[ Prime[n + 2] - Prime[n] - 2, {n, 75}] (* Robert G. Wilson v Oct 27 2004 *) Join[{1}, #[[3]]-#[[1]]-2&/@Partition[Prime[Range[90]], 3, 1]] (* Harvey P. Dale, Sep 26 2012 *) PROG (Haskell) a046930 1 = 1 a046930 n = subtract 2 \$ a031131 n  -- Reinhard Zumkeller, Dec 19 2013 CROSSREFS Related sequences: A023186-A023188, A046929-A046931, A051650, A051652, A051697-A051702, A051728-A051730. Sequence in context: A287393 A260085 A159461 * A302254 A160409 A035645 Adjacent sequences:  A046927 A046928 A046929 * A046931 A046932 A046933 KEYWORD nonn,easy,nice AUTHOR EXTENSIONS More terms from Michel ten Voorde STATUS approved

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Last modified July 18 07:46 EDT 2019. Contains 325136 sequences. (Running on oeis4.)