A075043 Primes for which the seven closest primes are smaller.

15683, 25471, 31397, 43801, 44293, 69499, 89689, 102701, 124367, 142993, 155921, 162293, 166871, 172441, 183527, 193891, 196201, 198859, 203461, 206827, 212701, 221101, 225167, 225383, 248909, 256219, 259033, 265621, 282713, 288583, 290249

Offset: 1

Author

Neil Fernandez, Oct 10 2002

Keywords

• nonn

Comments

If 9 consecutive primes are p1, p2, p3 ... p9, p8 is included in the sequence if p8-p1 is less than p9-p8. - Harvey P. Dale, Mar 25 2013

Examples

			The seven closest primes to 15683 are 15679 (difference = 4), 15671 (difference = 12), 15667 (difference = 16), 15661 (difference = 22), 15649 (difference = 34) and 15647 (difference = 36). These are all smaller than 15683 so 15683 is in the list.
		

Links

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

Crossrefs

Cf. A001223, A074979, A074982, A075030, A075037, A075038, A075050 and A075051.

Programs

Mathematica

NextPrim[n_] := Block[{k = n + 1}, While[ !PrimeQ[k], k++ ]; k]; ps = {0, 0, 0, 0, 0, 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, 26185}]
 Transpose[Select[Partition[Prime[Range[25000]],9,1],#[[8]]-#[[1]]<#[[9]]- #[[8]]&]][[8]](* Harvey P. Dale, Mar 25 2013 *)

Extensions

Edited and extended by Robert G. Wilson v, Oct 11 2002