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
KEYWORD
nonn
AUTHOR
Neil Fernandez, Oct 10 2002
EXTENSIONS
Edited by Robert G. Wilson v, Oct 11 2002
STATUS
approved