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 A138128 #13 Jun 26 2025 07:36:11
%S A138128 1,127,16129,2048383,260144641,33038369407,4195872914689,
%T A138128 532875860165503,67675234241018881,8594754748609397887,
%U A138128 1091533853073393531649,138624799340320978519423,17605349516220764271966721,2235879388560037062539773567,283956682347124706942551243009
%N A138128 Powers of 127.
%C A138128 127 is the 4th Mersenne prime A000668.
%H A138128 Paolo Xausa, <a href="/A138128/b138128.txt">Table of n, a(n) for n = 0..450</a>
%H A138128 <a href="/index/Rec#order_01">Index entries for linear recurrences with constant coefficients</a>, signature (127).
%F A138128 a(n) = 127^n.
%F A138128 From _Elmo R. Oliveira_, Jun 23 2025: (Start)
%F A138128 G.f.: 1/(1-127*x).
%F A138128 E.g.f.: exp(127*x).
%F A138128 a(n) = 127*a(n-1). (End)
%t A138128 127^Range[0, 15] (* _Paolo Xausa_, Jun 26 2025 *)
%o A138128 (PARI) my(x='x+O('x^15)); Vec(1/(1-127*x)) \\ _Elmo R. Oliveira_, Jun 23 2025
%Y A138128 Cf. A000668, A009975.
%K A138128 nonn,easy
%O A138128 0,2
%A A138128 _Omar E. Pol_, Mar 09 2008
%E A138128 More terms from _Elmo R. Oliveira_, Jun 23 2025