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Primes in A011371.
3

%I #10 Oct 10 2020 19:48:59

%S 3,7,11,19,23,31,41,47,53,67,71,73,79,89,97,101,109,113,127,131,137,

%T 149,173,181,191,193,197,229,239,263,271,277,281,293,311,337,349,353,

%U 359,367,383,389,397,401,421,431,439,449,461,463,467,479,487,491,499

%N Primes in A011371.

%C Primes p such that 2^p divides some factorial m!, but 2^(p+1) does not divide m!.

%H Amiram Eldar, <a href="/A181516/b181516.txt">Table of n, a(n) for n = 1..10000</a>

%t f[n_] := n - DigitCount[n, 2, 1]; s={}; Do[If[PrimeQ[(p = f[n])], AppendTo[s, p]], {n, 1, 510, 2}]; s (* _Amiram Eldar_, Sep 13 2019 *)

%t Select[Table[n-DigitCount[n,2,1],{n,0,600}],PrimeQ]//Union (* _Harvey P. Dale_, Oct 10 2020 *)

%Y Cf. A011371.

%K nonn

%O 1,1

%A _Vladimir Shevelev_, Oct 26 2010

%E Comment and definition swapped by _R. J. Mathar_, Oct 29 2010