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 A138127 #9 Aug 12 2023 00:56:11 %S A138127 0,127,254,381,508,635,762,889,1016,1143,1270,1397,1524,1651,1778, %T A138127 1905,2032,2159,2286,2413,2540,2667,2794,2921,3048,3175,3302,3429, %U A138127 3556,3683,3810,3937,4064,4191,4318,4445,4572,4699,4826,4953,5080 %N A138127 Multiples of 127. %C A138127 127 is the 4th Mersenne prime A000668. %H A138127 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (2,-1). %F A138127 a(n) = 127*n. %F A138127 From _Chai Wah Wu_, Aug 10 2023: (Start) %F A138127 a(n) = 2*a(n-1) - a(n-2) for n > 1. %F A138127 G.f.: 127*x/(x - 1)^2. (End) %e A138127 a(64)=8128 (The 4th perfect number A000396) because 127*64=8128. %t A138127 127*Range[0,40] (* _Harvey P. Dale_, Jan 17 2013 *) %Y A138127 Cf. A000396, A000668, A135631. %K A138127 easy,nonn %O A138127 0,2 %A A138127 _Omar E. Pol_, Mar 09 2008