login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A095056 Number of primes with three 1-bits (A081091) in range ]2^n,2^(n+1)]. 6
0, 1, 2, 1, 2, 3, 3, 0, 4, 2, 3, 2, 2, 2, 4, 1, 3, 4, 5, 3, 2, 1, 5, 1, 0, 2, 5, 2, 2, 8, 6, 0, 5, 3, 4, 2, 3, 2, 2, 0, 3, 5, 0, 1, 5, 3, 7, 0, 1, 2, 5, 1, 5, 2, 6, 0, 6, 0, 2, 3, 2, 1, 2, 0, 2, 3, 5, 3, 6, 2, 2, 2, 5, 2, 7, 1, 3, 2, 3, 1, 6, 2, 4, 3, 3, 2, 6, 1, 1, 5, 7, 2, 4, 2, 5, 0, 3, 4, 3, 1, 2, 1, 3, 0, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

T. D. Noe, Table of n, a(n) for n=1..1000

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

Samuel S. Wagstaff, Jr., Prime Numbers with a fixed number of one bits or zero bits in their binary representation, Exp. Math. vol. 10, issue 2 (2001) 267, Table 2. - From N. J. A. Sloane, Jun 19 2011.

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

EXAMPLE

From Michael De Vlieger, Feb 27 2017: (Start)

a(1) = 0 because there are no primes with three 1s in binary expansion between 2^1 and 2^2.

a(2) = 1 since the only prime between 2^2 and 2^3 with three 1s in binary expansion is 7 = binary 111.

a(3) = 2 since between 2^3 and 2^4 we have 11 and 13 (binary 1011 and 1101, respectively) have three 1s.

(End)

MATHEMATICA

Table[m = Count[Prime@ Range[PrimePi[2^n] + 1, PrimePi[2^(n + 1) - 1]], k_ /; DigitCount[k, 2, 1] == 3]; Print@ m; m, {n, 24}] (* Michael De Vlieger, Feb 27 2017 *)

CROSSREFS

Cf. A081504, A095018, A095057.

Sequence in context: A107853 A054758 A077876 * A186333 A272917 A239627

Adjacent sequences:  A095053 A095054 A095055 * A095057 A095058 A095059

KEYWORD

nonn

AUTHOR

Antti Karttunen and Labos Elemer, Jun 01 2004

EXTENSIONS

More terms from T. D. Noe, Oct 17 2007

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
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified August 15 12:59 EDT 2020. Contains 336502 sequences. (Running on oeis4.)