login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual appeal: Please make a donation to keep the OEIS running! Over 6000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A095005 Number of odious primes (A027697) in range ]2^n,2^(n+1)]. 6
0, 1, 2, 2, 5, 8, 19, 20, 48, 75, 160, 242, 505, 835, 1761, 2799, 5890, 10250, 20921, 36872, 74316, 134816, 267749, 492286, 977207, 1823657, 3598657, 6779899, 13336543, 25358424, 49763462, 95140695, 186504600 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..33.

A. Karttunen and J. Moyer, C-program for computing the initial terms of this sequence

Index entries for sequences related to occurrences of various subsets of primes in range ]2^n,2^(n+1)]

FORMULA

a(n) = A036378(n)-A095006(n).

MATHEMATICA

Table[Count[Prime@ Range[PrimePi[2^n] + 1, PrimePi[2^(n + 1) - 1]], k_ /; OddQ@ First@ DigitCount[k, 2]], {n, 24}] (* Michael De Vlieger, Feb 25 2017 *)

PROG

(PARI) a(n) = #select(x->((hammingweight(x)%2)==1), primes([2^n+1, 2^(n+1)])); \\ Michel Marcus, Feb 26 2017

CROSSREFS

Cf. A036378, A095006.

Sequence in context: A005834 A052531 A257517 * A209066 A208938 A019086

Adjacent sequences:  A095002 A095003 A095004 * A095006 A095007 A095008

KEYWORD

nonn

AUTHOR

Antti Karttunen and Labos Elemer, Jun 01 2004

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy .

Last modified December 11 12:00 EST 2017. Contains 295876 sequences.