A104884 Records in A104883.

4, 5, 8, 24, 54, 117, 222, 258, 291, 591, 888, 951, 1656, 1674, 2451, 2577, 4212, 4857, 6597, 7398, 10758, 10950, 11601, 19608, 20604, 27411, 35157, 43338, 45174, 46920, 53412, 71661, 90699, 96681, 107385, 123051, 130782, 189741, 225747, 273738, 288096, 362781

Offset: 1

Author

Benoit Cloitre and Robert G. Wilson v, Mar 28 2005

Keywords

• nonn

Comments

a(k) has the largest equal 'gap' between the nearest primes so far, i.e.; (the sum of the two nearest primes)/2 equals a(k).

Links

• Amiram Eldar, Table of n, a(n) for n = 1..72

Crossrefs

Cf. A104883, A082467.

Programs

Mathematica

f[n_] := Block[{k}, If[ OddQ[n], k = 2, k = 1]; While[ !PrimeQ[n - k] || !PrimeQ[n + k], k += 2]; k]; t = Table[f[n], {n, 4, 10^4}];u = Table[0, {80}]; Do[a = t[[n]]; If[a < 81 && u[[a]] == 0, u[[a]] = n + 3], {n, 10^4}]; a = 0; lst = {}; Do[ If[u[[n]] > a, a = u[[n]]; AppendTo[lst, a]], {n, 80}]; lst