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 A138336 #21 May 28 2025 00:29:00 %S A138336 18,27,127,1111 %N A138336 First occurrence of exactly n consecutive numbers after A138335(n) (A138335(n) excluded). %C A138336 Such number digits after decimal point of number Pi where the approximation to the number Pi by a root of a polynomial of 2 degree does not improve the accuracy exactly n next digits. %C A138336 It seems that sequence A138335, and therefore also this sequence, are ill defined. - _M. F. Hasler_, May 21 2025 %e A138336 a(1)=18 because 3.141592653589793238 (18 digits) is root of -3061495 + 674903*x + 95366*x^2 and 3.1415926535897932385 (19 digits) also is root of that same polynomial -3061495 + 674903*x + 95366*x^2. %Y A138336 Cf. A138335, A138337. %K A138336 nonn,dead %O A138336 1,1 %A A138336 _Artur Jasinski_, Mar 15 2008 %E A138336 There are comments in the entry for A138335 which may cast doubt on the validity of this and related sequences. - _N. J. A. Sloane_, Mar 19 2008