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 A138865 #10 Aug 23 2018 16:55:34 %S A138865 3,7,31,127,191,71,287,647,951,111,127,727,151,127,87,7,351,71,991, %T A138865 607,111,551,191,471,751,511,671,207,7,311,447,887,591,527,711,151, %U A138865 271,791,71,47,407,247,871,871,927,751,511 %N A138865 Last 3 digits of n-th Mersenne prime A000668(n). %H A138865 L. C. Noll, <a href="http://www.isthe.com/chongo/tech/math/prime/mersenne.html">Mersenne Prime Digits and Names</a>. %H A138865 Omar E. Pol, <a href="http://www.polprimos.com/#Los%20primos%20de%20Mersenne">Los primos de Mersenne</a> %t A138865 Array[Mod[2^MersennePrimeExponent[#] - 1, 1000] &, 45] (* _Michael De Vlieger_, Aug 05 2018 *) %Y A138865 Cf. A000668, A080173, A104511, A138862, A138863, A138864, A138866. %K A138865 base,nonn %O A138865 1,1 %A A138865 _Omar E. Pol_, Apr 02 2008 %E A138865 a(40)-a(47) from _Ivan Panchenko_, Apr 03 2018