cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A144214 Primes with both a prime number of 0's and a prime number of 1's in their binary representations.

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%I A144214 #19 Dec 27 2023 16:36:30
%S A144214 17,19,37,41,79,103,107,109,131,137,151,157,167,173,179,181,193,199,
%T A144214 211,227,229,233,241,257,367,379,431,439,443,463,487,491,499,521,541,
%U A144214 557,563,569,577,587,601,607,613,617,631,641,647,653,659,661,677,701,709
%N A144214 Primes with both a prime number of 0's and a prime number of 1's in their binary representations.
%H A144214 Michael S. Branicky, <a href="/A144214/b144214.txt">Table of n, a(n) for n = 1..10000</a>
%e A144214 79, a prime, in binary is 1001111. This has two 0's and has five 1's. Since both two and five are primes, 79 is included in the sequence.
%p A144214 A080791 := proc(n) local i,dgs ; dgs := convert(n,base,2) ; nops(dgs)-add(i,i=dgs) ; end: A000120 := proc(n) local i,dgs ; dgs := convert(n,base,2) ; add(i,i=dgs) ; end: isA144214 := proc(n) local no0,no1 ; no0 := A080791(n) ; no1 := A000120(n) ; isprime(n) and isprime(no0) and isprime(no1) ; end: for n from 1 to 1200 do if isA144214(n) then printf("%d,",n) ; fi; od: # _R. J. Mathar_, Sep 17 2008
%t A144214 Select[Prime[Range[6! ]],PrimeQ[DigitCount[ #,2,0]]&&PrimeQ[DigitCount[ #,2,1]]&] (* _Vladimir Joseph Stephan Orlovsky_, Feb 16 2010 *)
%o A144214 (Python)
%o A144214 from sympy import isprime
%o A144214 def ok(n): return isprime(c:=n.bit_count()) and isprime(n.bit_length()-c) and isprime(n)
%o A144214 print([k for k in range(710) if ok(k)]) # _Michael S. Branicky_, Dec 27 2023
%Y A144214 Cf. A081092, A144213, A178350.
%K A144214 base,nonn
%O A144214 1,1
%A A144214 _Leroy Quet_, Sep 14 2008
%E A144214 More terms from _R. J. Mathar_, Sep 17 2008