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 A053672 Least number coprime to n, n+1, n+2 and n+3. 3
 5, 7, 7, 11, 11, 5, 11, 7, 7, 7, 5, 11, 11, 11, 7, 5, 7, 11, 13, 13, 5, 7, 7, 7, 11, 5, 11, 11, 7, 7, 5, 13, 13, 11, 11, 5, 7, 7, 11, 11, 5, 13, 7, 7, 7, 5, 11, 11, 11, 7, 5, 7, 13, 13, 13, 5, 7, 7, 7, 11, 5, 11, 17, 7, 7, 5, 11, 11, 11, 11, 5, 7, 7, 13, 17, 5, 17, 7, 7, 7, 5, 11, 11, 11, 7 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Reinhard Zumkeller, Table of n, a(n) for n = 1..10000 FORMULA 5 <= a(n) <= (4 + o(1)) log n. - Charles R Greathouse IV, Jun 20 2013 MATHEMATICA a[n_] := (k = 5; While[ ! (CoprimeQ[k, n] && CoprimeQ[k, n+1] && CoprimeQ[k, n+2] && CoprimeQ[k, n+3]), k++]; k); Table[a[n], {n, 1, 85}](* Jean-François Alcover, Nov 30 2011 *) Table[Module[{k=3}, While[!And@@CoprimeQ[n+Range[0, 3], Prime[k]], k++]; Prime[k]], {n, 90}] (* Harvey P. Dale, May 10 2012 *) PROG (Haskell) import Data.List (elemIndex) import Data.Maybe (fromJust) a053672 n = 2 + fromJust    (elemIndex 1 \$ map (gcd \$ foldl1 lcm \$ take 4 [n..]) [2..]) -- Reinhard Zumkeller, Sep 25 2011 (PARI) a(n)=forprime(p=5, , if((n+3)%p>3, return(p))) \\ Charles R Greathouse IV, Jun 20 2013 CROSSREFS Cf. A053669-A053674, A226891. Sequence in context: A258316 A244621 A201459 * A087525 A078496 A114521 Adjacent sequences:  A053669 A053670 A053671 * A053673 A053674 A053675 KEYWORD nonn,easy,nice AUTHOR Henry Bottomley, Feb 15 2000 EXTENSIONS More terms from James A. Sellers, Feb 22 2000 STATUS approved

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Last modified November 19 10:48 EST 2018. Contains 317349 sequences. (Running on oeis4.)