

A294154


Base2 logarithm of product of primes between 2^n+1 and 2^(n+1).


0



1, 1, 5, 7, 22, 39, 84, 173, 367, 716, 1444, 2945, 5823, 11817, 23457, 47117, 94496, 188670, 378296, 755437, 1512435, 3024742, 6049260, 12099777, 24205776, 48402649, 96809896, 193632363, 387252738, 774544273, 1549044943
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OFFSET

0,3


COMMENTS

Inspired by Bertrand's postulate and complexity of algorithms using Farey fraction sets of size 2^n.
The log of this sequence seems linear after a few terms.


LINKS

Table of n, a(n) for n=0..30.


MATHEMATICA

Table[Floor[
Log[2, Times @@
Table[Prime[i], {i, PrimePi[2^(n)] + 1,
PrimePi[2^(n + 1)]}]]], {n, 0, 20}]


CROSSREFS

Cf. A036378 (number of primes between 2^n+1 and 2^(n+1).
Cf. A293696, A293697 (additive view of the primes between 2^n+1 and 2^(n+1).
Sequence in context: A036498 A248086 A076409 * A260658 A028281 A240102
Adjacent sequences: A294151 A294152 A294153 * A294155 A294156 A294157


KEYWORD

nonn,more,changed


AUTHOR

Olivier Gérard, Oct 24 2017


EXTENSIONS

a(26)a(30) from Robert Price, Nov 30 2017


STATUS

approved



