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 A134201 #25 Aug 09 2024 10:07:16 %S A134201 1,2,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, %T A134201 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, %U A134201 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6 %N A134201 Number of rigid hypergroups of order n. %C A134201 a(n) is also the number of I-toothpicks added to the structure of the cellular automaton of A323646 when starts its n-th cycle. Column 1 of triangle A323647. - _Omar E. Pol_, Nov 25 2019 %C A134201 Also decimal expansion of 19/15. - _Stefano Spezia_, Mar 23 2022 %D A134201 R. Bayon and N. Lygeros, Hyperstructures and Automorphism Groups, submitted. %D A134201 F. Marty, Sur une généralisation de la notion de groupe. In Proc. 8th Congr. des Mathématiciens Scandinaves, Stockholm, pp. 45-49, 1934. %D A134201 Th. Vougiouklis, The fundamental relation in hyperrings: The general hyperfield, Fourth Int. Congress Algebraic Hyperstructures and Appl. (AHA), 1991, pp. 203-211. %H A134201 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (1). %F A134201 a(1) = 1, a(2) = 2, a(n) = 6 for n > 2. %F A134201 G.f.: x*(1 + x + 4*x^2)/(1 - x). - _Stefano Spezia_, Mar 23 2022 %F A134201 E.g.f.: 6*exp(x) - 6 - 5*x - 2*x^2. - _Elmo R. Oliveira_, Aug 09 2024 %t A134201 Array[If[# <= 2, #, 6] &, 105] (* _Michael De Vlieger_, Dec 01 2019 *) %Y A134201 Cf. A108089, A132590, A134202, A323646, A323647. %K A134201 nonn,easy %O A134201 1,2 %A A134201 Roman Bayon (roman.bayon(AT)gmail.com), Oct 14 2007