A074979 Primes for which the two closest primes are smaller.

113, 139, 181, 199, 241, 283, 293, 317, 467, 509, 523, 577, 619, 661, 773, 829, 839, 863, 887, 953, 1021, 1039, 1069, 1129, 1237, 1307, 1327, 1381, 1459, 1499, 1583, 1627, 1637, 1669, 1699, 1759, 1789, 1879, 1913, 1951, 2003, 2039, 2089, 2113, 2143

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

The two closest primes to 113 are 109 (difference = 4) and 107 (difference = 6). Both 109 and 107 are smaller than 113, so 113 is in the list.

Mathematica

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; ps = {0, 0, 0, 1}; Do[ps = Drop[ps, 1]; ps = Append[ps, NextPrim[ ps[[ -1]]]]; If[ ps[[ -1]] - ps[[ -2]] > ps[[ -2]] - ps[[1]], Print[ ps[[ -2]]]], {n, 1, 330}]
Select[Partition[Prime[Range[400]], 4, 1], #[[3]]-#[[1]]<#[[4]]-#[[3]]&][[All, 3]] (* Harvey P. Dale, Aug 11 2021 *)

Crossrefs

Cf. A001223, A074982, A075030, A075037, A075038, A075043, A075050 and A075051.

Sequence in context: A140005 A198319 A124584 * A375974 A164920 A102833

Adjacent sequences: A074976 A074977 A074978 * A074980 A074981 A074982

Keyword

nonn

Author

Neil Fernandez, Oct 10 2002

Extensions

Edited by Robert G. Wilson v, Oct 11 2002

Status

approved