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%I #12 Nov 05 2019 20:19:25
%S 2,13,23,233,251,523,541,613,631,811,1009,1091,1109,1163,1181,1217,
%T 1307,1361,1433,1451,1523,1613,1721,1811,1901,2027,4153,4243,4261,
%U 4423,4441,4513,4603,4621,4801,5107,5233,5323,5413,5431
%N Prime numbers n whose digital sum equals the number of bits in its binary expansion.
%C Subset of A243615.
%H Andreas Boe, <a href="/A243619/b243619.txt">Table of n, a(n) for n = 1..10000</a>
%e 23 -> 2+3=5, 23=10111 -> Five bits.
%t Select[Prime[Range[800]],Total[IntegerDigits[#]]==IntegerLength[#,2]&] (* _Harvey P. Dale_, Nov 05 2019 *)
%o (PARI) isok(n) = isprime(n) && (sumdigits(n) == #binary(n)); \\ _Michel Marcus_, Jun 08 2014
%Y Cf. A243615 (same principle but covers all natural numbers).
%K nonn,base
%O 1,1
%A _Andreas Boe_, Jun 07 2014
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