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 A064890 #20 Oct 22 2024 09:48:36 %S A064890 1,7,7,0,6,7,5,2,4,4,3,2,5,5,8,0,2,2,7,9,1,9,7,9,6,0,0,7,6,4,2,6,6,0, %T A064890 8,0,2,2,3,3,1,8,3,7,6,7,2,7,2,8,3,3,5,2,0,5,2,2,4,5,8,9,6,4,4,1,2,2, %U A064890 2,0,3,3,8,1,0,2,2,9,6,1,1,0,5,6,5,0,7,0,5,7,7,5,7,0,8,0,9,3,4,0,3,3,3,0,2 %N A064890 Decimal expansion of the sum of reciprocals of A051451, which includes 1 and values of lcm(1,...,x), where x is a prime power (A000961). %H A064890 Nicholas John Bizzell-Browning, <a href="https://bura.brunel.ac.uk/handle/2438/29960">LIE scales: Composing with scales of linear intervallic expansion</a>, Ph. D. Thesis, Brunel Univ. (UK, 2024). See p. 37. %e A064890 c = 1.7706752443255802279197960076426608022331837672728335205224589644122203381... %e A064890 c = 1 + (1/2) + (1/6) + (1/12) + (1/60) + (1/420) + ... = 743/420 + ... = 1.7690 + ... = 1.7706752... Compare with A064859, an analogous constant obtained from A003418, where the constant is larger than c: 1.7877805 > 1.7706752. Repeated occurrences of LCM values in A003418 is responsible for the 1.78778... - 1.77067... = 0.0171... excess. %t A064890 f[n_] := LCM @@ Range@ n; RealDigits[ Plus @@ (1/Union@ Array[f, 251]), 10, 111][[1]] (* _Robert G. Wilson v_, Jul 11 2011 *) %Y A064890 Cf. A051451, A003418, A064859, A000961. %K A064890 cons,nonn %O A064890 1,2 %A A064890 _Labos Elemer_, Oct 11 2001