1,3

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)]

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)

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 *)

Cf. A081504, A095018, A095057.

Sequence in context: A107853 A054758 A077876 * A337557 A186333 A272917

Adjacent sequences: A095053 A095054 A095055 * A095057 A095058 A095059

nonn

Antti Karttunen and Labos Elemer, Jun 01 2004

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

approved