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A160666 Numbers whose distance to the closest prime number is a prime number. 1
0, 9, 15, 21, 25, 26, 27, 33, 34, 35, 39, 45, 49, 50, 51, 55, 56, 57, 63, 64, 65, 69, 75, 76, 77, 81, 85, 86, 87, 91, 92, 94, 95, 99, 105, 111, 115, 116, 118, 120, 122, 124, 125, 129, 133, 134, 135, 141, 142, 144, 146, 147, 153, 154, 155, 159, 160, 161, 165, 169, 170 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Terms n=2..31 are identical to terms n=1..30 of A079364.

LINKS

K. Stern, Table of n, a(n) for n=1..10000

MAPLE

isA160666 := proc(n) local ppl, pmi ; if isprime(n) then RETURN(false): elif n =0 then RETURN(true): elif n =1 then RETURN(false): fi; ppl := nextprime(n)-n ; pmi := n-prevprime(n) ; RETURN (isprime(min(ppl, pmi)) ) ; end: for n from 0 to 200 do if isA160666(n) then printf("%d, ", n) ; fi; od: # R. J. Mathar, May 25 2009

MATHEMATICA

fQ[n_] := PrimeQ[ Min[ NextPrime[n] - n, n - NextPrime[n, -1]]]; Select[ Range[0, 174], !PrimeQ@ # && fQ@# &] (* Robert G. Wilson v, May 25 2009 *)

CROSSREFS

Cf. A000040, A051699.

Sequence in context: A321342 A255763 A079364 * A039769 A270574 A071904

Adjacent sequences:  A160663 A160664 A160665 * A160667 A160668 A160669

KEYWORD

nonn

AUTHOR

Kyle Stern, May 22 2009

EXTENSIONS

More terms from R. J. Mathar and Robert G. Wilson v, May 25 2009

STATUS

approved

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Last modified November 17 06:06 EST 2019. Contains 329217 sequences. (Running on oeis4.)