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 A088037 #16 Mar 16 2024 04:33:43 %S A088037 4,9,9,49,225,961,3969,16129,65025,261121,1046529,4190209,16769025, %T A088037 67092481,268402689,1073676289,4294836225,17179607041,68718952449, %U A088037 274876858369,1099509530625,4398042316801,17592177655809 %N A088037 Smallest square k == 1 (mod some n-th power), k > 1. %C A088037 From a(2) onwards the n-th power that divides a(n) -1 is 2^n ===> Second term onwards same as A060867 i.e. a(n+1) = (2^n-1)^2. %H A088037 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (7,-14,8). %F A088037 From _Colin Barker_, Feb 05 2013: (Start) %F A088037 a(n) = (2^n-2)^2/4 for n>2. %F A088037 a(n) = 7*a(n-1)-14*a(n-2)+8*a(n-3) for n>5. %F A088037 G.f.: x*(2*x+1)*(32*x^3-56*x^2+27*x-4) / ((x-1)*(2*x-1)*(4*x-1)). (End) %e A088037 a(6) = 961 and 960 = 64*15. %Y A088037 Cf. A060867. %K A088037 nonn,easy %O A088037 1,1 %A A088037 _Amarnath Murthy_, Sep 19 2003 %E A088037 More terms from _Ray Chandler_, Oct 04 2003