Smallest prime a(n) such that a(n)-x and a(n)+x, for x=1 to n, are all composite.

Terms

a(0) =5a(1) =23a(2) =23a(3) =53a(4) =53a(5) =211a(6) =211a(7) =211a(8) =211a(9) =211a(10) =211a(11) =1847a(12) =1847a(13) =2179a(14) =2179a(15) =2179a(16) =2179a(17) =3967a(18) =3967a(19) =16033a(20) =16033a(21) =16033a(22) =16033a(23) =24281a(24) =24281a(25) =24281a(26) =24281a(27) =24281a(28) =24281a(29) =38501