A160666 Numbers whose distance to the closest prime number is a prime number.

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

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: A333312 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