A225583 Primes in the chain of repeated application of x->2*x+3, starting at x=19.

19, 41, 173, 349, 701, 11261, 45053, 180221, 184549373, 738197501, 5905580029, 188978561021, 6192449487634429, 49539595901075453, 99079191802150909, 25364273101350633469, 811656739243220271101, 3486039150627630854115933814781

Offset

1,1

Comments

Primes in A156198.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..37

Mathematica

Select[NestList[2 # + 3 &, 19, 30], PrimeQ] (* or *) Select[Table[11 2^n - 3, {n, 0, 150}], PrimeQ]

Prog

(Magma) x:=19; a:=[n eq 1 select x else 2*Self(n-1)+3: n in [1..200]]; [a[i]: i in [1..#a] | IsPrime(a[i])]; /* or */ [a: n in [0..150] | IsPrime(a) where a is 11*2^n-3];

Crossrefs

Primes of the form k*2^m-3: A050415 (k=1), A173769 (k=5), A225582 (k=7), this sequence (k=11), A225584 (k=13); A172156 (k=100), A163589 (k=715).

Numbers of the form 11*2^m-3: A156198.

Sequence in context: A141855 A323387 A328493 * A180932 A140603 A139580

Adjacent sequences: A225580 A225581 A225582 * A225584 A225585 A225586

Keyword

nonn

Author

Vincenzo Librandi, May 14 2013

Status

approved