A118741 Primes for which the weight as defined in A117078 is 7.

67, 83, 167, 193, 251, 277, 433, 487, 503, 587, 601, 613, 727, 823, 907, 1063, 1217, 1231, 1553, 1663, 1777, 1861, 1873, 1973, 1987, 2083, 2281, 2293, 2351, 2377, 2393, 2797, 2897, 3217, 3343, 3541, 3847, 4073, 4283, 4451, 4507, 4591, 4813, 4871, 5081

Offset

1,1

Comments

The gap as defined in A001223 of this prime numbers is 4 or 6.

The prime numbers in this sequence are of the form (14i-1) (if gap=6) or (14i-3) (if gap=4) with i=(level(n)+1)/2, level(n) defined in A117563.

Links

Remi Eismann, Table of n, a(n) for n=1..10000

Formula

A117078 : a(n) = smallest k such that prime(n+1) = prime(n) + (prime(n) mod k), or 0 if no such k exists. prime(n) for which k=7.

Mathematica

f[n_] := Block[{a, p = Prime[n], np = Prime[n + 1]}, a = Min[Select[Divisors[2*p - np], #1 > np - p & ]]; If[a == Infinity, 0, a]]; Prime@ Select[ Range@695, f@# == 7 &] (* Robert G. Wilson v, May 26 2006 *)

Crossrefs

Cf. A117078, A117563, A118922, A118924.

Sequence in context: A091075 A288409 A139973 * A217115 A130058 A207293

Adjacent sequences: A118738 A118739 A118740 * A118742 A118743 A118744

Keyword

nonn

Author

Rémi Eismann, May 22 2006; May 27 2006; May 04 2007

Extensions

More terms from Robert G. Wilson v, May 26 2006

Status

approved