

A272143


For a given n, and any m less than n1, the total number of primes of the form 2^n2^m1.


1



0, 1, 1, 2, 2, 3, 0, 4, 4, 3, 1, 5, 1, 4, 0, 3, 2, 8, 1, 11, 4, 5, 0, 7, 1, 2, 0, 1, 5, 4, 0, 7, 5, 1, 1, 9, 0, 6, 0, 7, 1, 6, 0, 4, 7, 2, 1, 10, 3, 3, 1, 2, 1, 6, 0, 4, 3, 0, 1, 8, 3, 3, 0, 3, 1, 8, 1, 2, 2, 3, 0, 9, 1, 5, 2, 5, 8, 3, 0, 10
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,4


COMMENTS

For the first 12000 terms the average is ~3.8 with a maximum of 25 at a(11520).
Essentially the same as A095058.  R. J. Mathar, Apr 24 2016


LINKS

Hans Havermann, Table of n, a(n) for n = 1..12000
Hans Havermann, Table of n, {m1, m2, ...} for primes of the form 2^n2^m1, m<n1.


EXAMPLE

For n=1, m<0, so there are no solutions. For n=2 there is one solution: m=0, yielding prime 2. For n=3, one solution: m=1, yielding prime 5. For n=4 there are two solutions: m=2 and m=1, yielding primes 11 and 13 respectively. The primes so formed are terms of A095078.


MATHEMATICA

Table[Length[Select[Table[2^n  2^m  1, {m, 0, n  2}], PrimeQ[#] & ]], {n, 1, 100}] (* Robert Price, Apr 21 2016 *)


CROSSREFS

Cf. A095078.
Sequence in context: A263254 A257989 A095201 * A095058 A137345 A060755
Adjacent sequences: A272140 A272141 A272142 * A272144 A272145 A272146


KEYWORD

nonn


AUTHOR

Hans Havermann, Apr 21 2016


STATUS

approved



