A053073 Balanced primes separated from the next lower and next higher prime neighbors by 18.

20201, 21911, 25391, 29269, 30449, 34631, 50441, 54851, 56149, 58129, 63559, 66431, 74471, 74489, 76561, 76579, 77951, 78259, 81439, 107581, 108439, 110459, 112181, 121421, 122099, 122579, 131041, 132911, 132929, 135301, 137321, 137849

Offset: 1

Author

Harvey P. Dale, Feb 25 2000

Keywords

• easy
• nonn

Examples

			25391 is separated from both the next lower prime and the next higher prime by 18.
		

Links

• Zak Seidov, Table of n, a (n) for n = 1..1000

Crossrefs

Cf. A052189.

Programs

Mathematica

lst={};Do[p=Prime[n];If[p-Prime[n-1]==Prime[n+1]-p==6*3,AppendTo[lst,p]],{n,2,3*7!}];lst (* Vladimir Joseph Stephan Orlovsky, May 20 2010 *)
Transpose[Select[Partition[Prime[Range[20000]],3,1],Differences[#] == {18,18}&]][[2]] (* Harvey P. Dale, Oct 21 2011 *)

Formula

a(n) = A052189(n) + 18. - Sean A. Irvine, Dec 05 2021