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A046929 Width of moat of composite numbers surrounding n-th prime. 17
0, 0, 1, 1, 1, 1, 1, 1, 3, 1, 1, 3, 1, 1, 3, 5, 1, 1, 3, 1, 1, 3, 3, 5, 3, 1, 1, 1, 1, 3, 3, 3, 1, 1, 1, 1, 5, 3, 3, 5, 1, 1, 1, 1, 1, 1, 11, 3, 1, 1, 3, 1, 1, 5, 5, 5, 1, 1, 3, 1, 1, 9, 3, 1, 1, 3, 5, 5, 1, 1, 3, 5, 5, 5, 3, 3, 5, 3, 3, 7, 1, 1, 1, 1, 3, 3, 5, 3, 1, 1, 3, 7, 3, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,9

LINKS

T. D. Noe, Table of n, a(n) for n=1..10000

Jean-François Alcover, Frequency distribution up to 10^6 terms.

EXAMPLE

23 has a buffer of 3 composites around it on each side: 20,21,22,23,24,25,26.

MAPLE

with(numtheory); a := i->min(ithprime(n)-ithprime(n-1)-1, ithprime(n+1)-ithprime(n)-1);

MATHEMATICA

a[n_] := Min[Prime[n] - Prime[n-1] - 1, Prime[n+1] - Prime[n] - 1]; a[1] = 0; Table[a[n], {n, 1, 100}] (* Jean-François Alcover, Apr 16 2013 *)

Join[{0}, Min[Differences[#]]&/@Partition[Prime[Range[100]], 3, 1]-1] (* Harvey P. Dale, Feb 24 2014 *)

CROSSREFS

Related sequences: A023186-A023188, A046929-A046931, A051650, A051652, A051697-A051702, A051728-A051730.

Sequence in context: A060266 A073310 A174414 * A068695 A110787 A325982

Adjacent sequences:  A046926 A046927 A046928 * A046930 A046931 A046932

KEYWORD

nonn,easy,nice

AUTHOR

N. J. A. Sloane

STATUS

approved

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Last modified August 26 05:42 EDT 2019. Contains 326329 sequences. (Running on oeis4.)