A074979 - OEIS

%I #10 Aug 11 2021 11:08:36

%S 113,139,181,199,241,283,293,317,467,509,523,577,619,661,773,829,839,

%T 863,887,953,1021,1039,1069,1129,1237,1307,1327,1381,1459,1499,1583,

%U 1627,1637,1669,1699,1759,1789,1879,1913,1951,2003,2039,2089,2113,2143

%N Primes for which the two closest primes are smaller.

%H Harvey P. Dale, <a href="/A074979/b074979.txt">Table of n, a(n) for n = 1..1000</a>

%e 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.

%t 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}]

%t Select[Partition[Prime[Range[400]],4,1],#[[3]]-#[[1]]<#[[4]]-#[[3]]&][[All,3]] (* _Harvey P. Dale_, Aug 11 2021 *)

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

%K nonn

%O 1,1

%A _Neil Fernandez_, Oct 10 2002

%E Edited by _Robert G. Wilson v_, Oct 11 2002