A084314 a(n) = x is the smallest number such that gcd(prime(x)+1, x) = n.

1, 2, 3, 4, 35, 24, 63, 56, 45, 10, 649, 132, 91, 42, 495, 48, 153, 54, 779, 700, 1785, 264, 851, 96, 1125, 286, 1647, 672, 551, 570, 341, 448, 2277, 1462, 385, 144, 1369, 418, 2145, 1000, 4797, 294, 817, 1804, 405, 414, 7003, 2016, 11515, 950, 2193, 2444

Offset: 1

Author

Labos Elemer, Jun 13 2003

Keywords

• nonn

Links

• Ivan Neretin, Table of n, a(n) for n = 1..4000

Crossrefs

Cf. A084309-A084316.

Programs

Mathematica

f[x_] := GCD[Prime[x]+1, x] t=Table[0, {256}]; Do[s=f[n]; If[s<257&&t[[s]]==0, t[[s]]=n], {n, 1, 100000}]; t
Module[{cc=Table[{x,GCD[Prime[x]+1,x]},{x,20000}]},Transpose[Table[ SelectFirst[ cc,#[[2]]==n&],{n,60}]][[1]]] (* Harvey P. Dale, Nov 28 2014 *)

Formula

a(n) = Min{x; A084310(x)=n}.