A392111 Numbers k such that 5*k - (greatest prime < 5*k) = (least prime > 5*k) - 5*k.

1, 3, 6, 9, 10, 12, 21, 24, 30, 32, 33, 34, 36, 39, 41, 45, 48, 52, 54, 60, 63, 74, 81, 84, 93, 99, 103, 112, 114, 118, 120, 122, 123, 125, 129, 130, 132, 135, 136, 141, 146, 153, 156, 162, 165, 171, 174, 177, 183, 190, 192, 196, 204, 210, 219, 220, 224, 228

Offset

1,2

Links

Table of n, a(n) for n=1..58.

Formula

a(n) = A268328(n-1). - Amiram Eldar, Jan 21 2026

Mathematica

m = 5; z = 140;
u[n_] := NextPrime[m n, -1]; v[n_] := NextPrime[m n];
Select[Range[400], m*# - v[#] < u[#] - m*# &]   (* A392110 *)
Select[Range[400], m*# - v[#] == u[#] - m*# &]  (* A392111 *)
Select[Range[400], m*# - v[#] > u[#] - m*# &]   (* A392112 *)
fQ[n_] := 10n == NextPrime[ 5n, -1] + NextPrime[ 5n]; Select[ Range[ 228], fQ] (* Robert G. Wilson v, Jan 31 2026 *)

Crossrefs

Cf. A000027, A000040, A268328, A390788, A392110, A392112.

Sequence in context: A372850 A363950 A268328 * A247575 A338626 A289130

Adjacent sequences: A392108 A392109 A392110 * A392112 A392113 A392114

Keyword

nonn

Author

Clark Kimberling, Jan 15 2026

Status

approved