A059394 Special safe primes (from A005385) such that the next prime is also a safe prime.

5, 7, 467, 1307, 2447, 5087, 5927, 12527, 18947, 44687, 55079, 78467, 79943, 83207, 93383, 103007, 105143, 111443, 118787, 128879, 143687, 164987, 196907, 204587, 207227, 208787, 229487, 232823, 236507, 257627, 267143, 275987, 289319, 296159

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

For {467,55079,103007,728579,887759,..} safe primes {479,55103,103043,728627,887819} are the next primes, whose differences are 12,24,36,48,60,.. respectively,not necessarily equal to 12, the possible minimum (see A059322).

Mathematica

ss[x_] := PrimeQ[(Prime[x]-1)/2]&&PrimeQ[(Prime[x+1]-1)/2] t=Prime[Flatten[Position[Table[ss[w], {w, 1, 100000}], True]]]

Crossrefs

Cf. A005385, A005384, A059322, A059323, A059327.

Sequence in context: A196331 A344361 A159019 * A176960 A114368 A260830

Adjacent sequences: A059391 A059392 A059393 * A059395 A059396 A059397

Keyword

nonn

Author

Labos Elemer, Jan 29 2001

Status

approved