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 A108155 #10 Jun 02 2025 00:27:54 %S A108155 -1,0,1,2,3,4,5,6,7,8,9,10,14,15,16,17,18,30,31,32,33,34,62,63,64,65, %T A108155 66,126,127,128,129,130,254,255,256,257,258,510,511,512,513,514,1022, %U A108155 1023,1024,1025,1026,2046,2047,2048,2049,2050,4094,4095,4096,4097,4098,8190,8191,8192,8193,8194,16382,16383,16384 %N A108155 Numbers of the forms 2^n-2, 2^n-1, 2^n, 2^n+1 and 2^n+2. %C A108155 This number sequence is designed for a quick test of e.g. arithmetic in binary systems. %H A108155 <a href="/index/Rec#order_09">Index entries for linear recurrences with constant coefficients</a>, signature (-1,-1,-1,-1,2,2,2,2,2). %F A108155 Union of A000918, A000225, A000079, A000051, and A052548. %Y A108155 Cf. A107684. %K A108155 sign %O A108155 1,4 %A A108155 Henrik Lundquist (sploinker(AT)sploink.dk), Jun 06 2005