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Number of odious primes (A027697) in range ]2^n,2^(n+1)].
6

%I #18 Jun 20 2024 02:37:19

%S 0,1,2,2,5,8,19,20,48,75,160,242,505,835,1761,2799,5890,10250,20921,

%T 36872,74316,134816,267749,492286,977207,1823657,3598657,6779899,

%U 13336543,25358424,49763462,95140695,186504600,358630024,702300885,1356118149,2654709953,5142968571

%N Number of odious primes (A027697) in range ]2^n,2^(n+1)].

%H Antti Karttunen and John Moyer, <a href="/A095062/a095062.c.txt">C-program for computing the initial terms of this sequence</a>.

%H <a href="/index/Pri#primesubsetpop2">Index entries for sequences related to occurrences of various subsets of primes in range ]2^n,2^(n+1)]</a>.

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

%t 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 *)

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

%Y Cf. A027697, A036378, A095006.

%K nonn

%O 1,3

%A _Antti Karttunen_ and _Labos Elemer_, Jun 01 2004

%E a(34)-a(38) from _Amiram Eldar_, Jun 20 2024

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Last modified September 22 14:04 EDT 2024. Contains 376114 sequences. (Running on oeis4.)