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 A080172 #27 Sep 16 2024 09:24:17 %S A080172 3,7,1,7,1,1,7,7,1,1,7,7,1,7,7,7,1,1,1,7,1,1,1,1,1,1,1,7,7,1,7,7,1,7, %T A080172 1,1,1,1,1,7,7,7,1,1,7,1,1,1 %N A080172 Final digit of n-th Mersenne prime A000668(n). %C A080172 Distribution of final digit for Mersenne primes appears (naturally) to be different from distribution for regular primes. Unconfirmed 49th, 50th and 51st digits in sequence are 1, 1, 1 (awaiting confirmation of 49th, 50th and 51st Mersenne primes). %D A080172 G. H. Hardy and E. M. Wright, An Introduction to the Theory of Numbers. 3rd ed., Oxford Univ. Press, 1954, p. 16. %H A080172 Great Internet Mersenne Prime Search (GIMPS), <a href="http://www.mersenne.org/">Distributed Computing Projects</a> %H A080172 Mersenne Primes, <a href="http://www.utm.edu/research/primes/mersenne/index.html">History, Theorems and Lists</a> %p A080172 (Maple code from _N. J. A. Sloane_) # let s1 := list of terms in A000043 %p A080172 f:=n->if n mod 4 = 0 then 4 else n mod 4; fi; map(x->2^f(x)-1,s1); %t A080172 Mod[2^MersennePrimeExponent[Range[48]]-1,10] (* _Harvey P. Dale_, Aug 09 2023; updated by _Mark Dowdeswell_, Sep 16 2024 *) %Y A080172 Cf. A000668, A007652, A080173. %K A080172 base,more,nonn %O A080172 1,1 %A A080172 _Mark Dowdeswell_, Feb 04 2003 %E A080172 Updated by _N. J. A. Sloane_, Apr 01 2008 %E A080172 a(40)-a(47) from _Ivan Panchenko_, Apr 11 2018 %E A080172 a(48) from _Mark Dowdeswell_, Sep 16 2024