A096480 a(n) = Min{x : A073124(x) = 2n}.

1, 8, 5, 22, 16, 15, 33, 67, 62, 164, 88, 56, 73, 202, 134, 504, 201, 261, 799, 1461, 289, 282, 1309, 1053, 1143, 939, 527, 3531, 2179, 4751, 2461, 5308, 2837, 3983, 1946, 8622, 9488, 12862, 6377, 4653, 7594, 7646, 19251, 22538, 9561, 32509, 26146, 17568

Offset

1,2

Links

Amiram Eldar, Table of n, a(n) for n = 1..214

Example

For n = 4: a(4) = 22 since A073124(22) = prime(1+prime(22)) - prime(prime(22)) = prime(1+79) - prime(79) = 409 - 401 = 8.
For n = 5: a(5) = 16 since A073124(16) = prime(1+prime(16)) - prime(prime(16)) = prime(54) - prime(53) = 251 - 241 = 10.

Mathematica

Table[Min[Flatten[Position[Table[Prime[Prime[n]+1]- Prime[Prime[n]], {n, 1, 5000}], 2*j]]], {j, 1, 20}]
seq[max_] := Module[{p = Prime[Range[max + 1]], m = PrimePi[max], ind, t}, ind = Prime[Range[m]]; t = p[[ind + 1]] - p[[ind]]; TakeWhile[FirstPosition[t, 2*#] & /@ Range[Max[t]] // Flatten, ! MissingQ[#] &]]; seq[10^6] (* Amiram Eldar, Feb 15 2025 *)

Prog

(PARI) {m=48; for(n=1, m, k=1; while((prime(prime(k)+1)-prime(prime(k)))!=2*n, k++); print1(k, ", "))} \\ Klaus Brockhaus, Jun 27 2004

Crossrefs

Cf. A000040, A006450, A073124, A072677, A096477, A096478, A096479, A096481, A096482.

Sequence in context: A348688 A199806 A070484 * A248292 A196123 A196120

Adjacent sequences: A096477 A096478 A096479 * A096481 A096482 A096483

Keyword

nonn

Author

Labos Elemer, Jun 23 2004

Extensions

a(31)-a(48) from Klaus Brockhaus, Jun 27 2004

Status

approved