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.
%I A339766 #24 Jul 29 2021 11:04:23
%S A339766 2,6,1,2,0,0,0,7,4,0,4,3,4,5,2,6,0,6,4,4,3,7,3,7,1,1,3,0,9,5,4,4,5,6,
%T A339766 7,2,4,3,3,4,0,4,5,8,7,3,7,0,9,3,8,2,6,6,0,9,3,5,1,0,8,0,6,0,5,1,5,6,
%U A339766 0,4,1,0,8,8,7,4,9,3,0,1,3,6,2,5,1,3,6
%N A339766 Decimal expansion of Sum_{n>=1} A054541(n)/A076954(n-1).
%C A339766 With this constant f(1) and using the formula f(n+1) = (floor(f(n))*(f(n))) - ((floor(f(n)))^2 - floor(f(n))) it is possible to obtain the prime numbers repeated exactly a number of times corresponding to the position of the prime number. That is, 2 once, 3 twice, 5 thrice, etc.
%F A339766 Equals 2 + (3-2)/(2) + (5-3)/(2*3^2) + (7-5)/(2*3^2*5^3) + (11-7)/(2*3^2*5^3*7^4) + ...
%e A339766 2.61200074043...
%t A339766 imax:=87;First[RealDigits[N[2+Sum[(Prime[i]-Prime[i-1])/Product[Prime[j-1]^(j-1),{j,2,i}],{i,2,imax}],imax]]] (* _Stefano Spezia_, Dec 16 2020 *)
%Y A339766 Cf. A054541, A076954, A005145, A249270.
%K A339766 nonn,cons
%O A339766 1,1
%A A339766 _Davide Rotondo_, Dec 16 2020