A050666 Primes p such that number of primes produced according to rules stipulated in Honaker's A048853 is 4.

97, 389, 659, 743, 953, 2423, 2971, 3037, 3083, 3593, 3727, 4177, 4363, 4813, 4889, 5261, 5519, 5717, 5813, 5939, 6197, 6449, 7001, 7057, 7331, 7963, 8123, 8179, 8353, 8501, 8707, 9293, 9587, 10247, 11261, 13147, 14813, 15263, 16547, 17573, 18077

Offset

1,1

Links

Table of n, a(n) for n=1..41.

Example

Altering a(1)=97 gives 4 primes: 17, 37, 47 and 67.

Mathematica

A048853[n_] := Module[{idn = IntegerDigits[n], id, np = 0}, Do[id = idn; If[id[[j]] != k, id[[j]] = k; If[id[[1]] != 0 && PrimeQ[FromDigits[id]], np = np + 1]], {j, 1, Length[idn]}, {k, 0, 9}]; np]; Select[Table[{p, A048853[p]}, {p, Prime[Range[3000]]}], #[[2]] == 4&][[All, 1]] (* Jean-François Alcover, May 09 2017 *)

Crossrefs

Cf. A048853, A050673, A050655.

Sequence in context: A105128 A031927 A174338 * A160440 A107213 A157331

Adjacent sequences: A050663 A050664 A050665 * A050667 A050668 A050669

Keyword

nonn,base

Author

Patrick De Geest, Jul 15 1999

Status

approved