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 A169681 #17 Apr 05 2024 16:53:56 %S A169681 1,7,0,1,4,1,1,8,3,4,6,0,4,6,9,2,3,1,7,3,1,6,8,7,3,0,3,7,1,5,8,8,4,1, %T A169681 0,5,7,2,7 %N A169681 Decimal expansion of 2^127-1. %C A169681 The 12th Mersenne prime, A000668(12); 127 = A000043(12). Also, the fifth Catalan number A007013(4). - _M. F. Hasler_, Jan 09 2013 %H A169681 Wikipedia, <a href="http://en.wikipedia.org/wiki/Mersenne_prime">Mersenne prime</a> %F A169681 2^127-1 = 2^A000043(12)-1 = A000668(12). - _M. F. Hasler_, Jan 09 2013 %e A169681 170141183460469231731687303715884105727. %t A169681 IntegerDigits[2^127 - 1] (* _Paolo Xausa_, Apr 05 2024 *) %o A169681 (Magma) Reverse(Intseq(2^127-1)); // _Arkadiusz Wesolowski_, Oct 18 2014 %Y A169681 Cf. A169684 = A000668(11), A169685 = A000668(13), A204063 = A000668(14), A248931 = A000668(15), A248932 = A000668(16), A248933 = A000668(17), A248934 = A000668(18), A248935 = A000668(19), A248936 = A000668(20). %K A169681 nonn,cons,easy,fini,full %O A169681 39,2 %A A169681 _Vincenzo Librandi_, Apr 12 2010 %E A169681 Edited by _N. J. A. Sloane_, Apr 13 2010