%I #36 Jun 07 2024 09:52:27
%S 0,1,2,2,3,3,4,4,4,4,5,5,6,6,6,6,7,7,8,8,8,8,9,9,9,9,9,9,1,0,1,0,1,1,
%T 1,1,1,1,1,1,1,1,1,1,1,2,1,2,1,2,1,2,1,3,1,3,1,4,1,4,1,4,1,4,1,5,1,5,
%U 1,5,1,5,1,5,1,5,1,6,1,6,1,6,1,6,1,6
%N Successive digits of consecutive terms of the prime-counting function A000720.
%C By analogy with the Copeland-Erdős constant 0.2357111317... given by concatenating the base-10 expansions of consecutive entries of the sequence of prime numbers, the so-called "prime-counting Copeland-Erdős constant" 0.0122...9101011... is defined similarly, but with the use of the prime-counting function in place of the prime number sequence.
%H Michael De Vlieger, <a href="/A366033/b366033.txt">Table of n, a(n) for n = 0..10000</a>
%H John M. Campbell, <a href="https://arxiv.org/abs/2309.13520">The prime-counting Copeland-Erdős constant</a>, arXiv:2309.13520 [math.NT], 2023.
%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ConsecutiveNumberSequences.html">Consecutive Number Sequences</a>.
%H Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Prime-CountingConcatenationConstant.html">Prime-Counting Concatenation Constant</a>.
%e 0.012233444455666677888899999910101111...
%e The prime-counting function evaluated at 1 is 0, so a(0) = 0, and the first digit after the decimal point of the prime-counting Copeland-Erdős constant is 0.
%t Flatten[Table[IntegerDigits[PrimePi[n]], {n, 1, 57}]]
%t Flatten[IntegerDigits[PrimePi[Range[57]]]] (* _Eric W. Weisstein_, Jun 07 2024 *)
%o (PARI) concat(0, concat(vector(50, i, digits(primepi(i))))) \\ _Michel Marcus_, Nov 04 2023
%Y Cf. A000720, A001191, A033307, A033308.
%K nonn,cons,base
%O 0,3
%A _John M. Campbell_, Sep 26 2023