A244086 Primes p such that p remains prime through 7 iterations of function f(x) = 2*x + 3.

477727, 507757, 30596497, 33145687, 36180527, 61192997, 141339217, 148590307, 193394347, 297180617, 374066267, 395534747, 398001547, 419795137, 488716897

Offset

1,1

Links

Table of n, a(n) for n=1..15.

Mathematica

Select[Prime[Range[600000]], And@@PrimeQ[NestList[2 # + 3 &, #, 7]] &]

Prog

(Magma) [p: p in PrimesUpTo(600000000) | forall{i: i in [1..7] | IsPrime(2^i*p+3*(2^i-1))}];

Crossrefs

Cf. similar sequences with k iterations: A067076 (k=1), A023242 (k=2), A023273 (k=3), A023303 (k=4), A023331 (k=5), A175160 (k=6), this sequence (k=7).

Sequence in context: A201226 A244628 A290050 * A015332 A238178 A250714

Adjacent sequences: A244083 A244084 A244085 * A244087 A244088 A244089

Keyword

nonn,easy

Author

Vincenzo Librandi, Jun 24 2014

Extensions

Inappropriate MAGMA code simplified and other terms added from Bruno Berselli, Jun 24 2014

Status

approved