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%I #9 Jan 27 2019 10:42:58
%S 2,3,5,7,11,31,41,43,53,61,71,73,83,97,101,211,311,313,331,401,421,
%T 431,433,443,503,521,523,541,601,613,631,641,643,653,661,701,727,733,
%U 743,751,757,761,773,811,821,823,827,853,857,863,877,881,883,887,907,911
%N Primes where the first digit is equal to the largest digit.
%C The upper asymptotic density is 1/9 and the lower asymptotic density is 1/81, due to the Prime Number Theorem.
%e 2(2=2), 3(3=3), 5(5=5), 7(7=7), 31(3=3>1), 41(4=4>1), 43(4=4>3), etc.
%p a := proc (n) local nn, nnn: nn := convert(ithprime(n), base, 10): nnn := seq(nn[j], j = 1 .. nops(nn)): if nn[nops(nn)] = max(nnn) then ithprime(n) else end if end proc: seq(a(n), n = 1 .. 200); # _Emeric Deutsch_, Mar 02 2009
%K nonn,base,less
%O 1,1
%A _Juri-Stepan Gerasimov_, Feb 24 2009
%E 11, 313 etc. inserted by _Emeric Deutsch_ and _R. J. Mathar_, Feb 26 2009
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