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 A114011 #4 Dec 05 2013 19:57:13
%S A114011 21,11,91,51,171,161,261,31,111,41,301,141,371,531,61,201,71,511,711,
%T A114011 581,801,291,101,721,321,981,791,381,131,411,1251,1341,151,471,1141,
%U A114011 501,1211,1611,181,191,1351,591,1791,211,1561,681,2061,1631,2151,241,251
%N A114011 Least multiple of prime(n) ending in digit 1.
%e A114011 a(9) = 161 == 0 (mod prime(9)=23).
%t A114011 f[n_] := Block[{k = 1, p = Prime[n]}, While[Mod[k*p, 10] != 1, k++ ]; k*p]; Table[ f[n], {n, 4, 54}] (* _Robert G. Wilson v_ *)
%Y A114011 Cf. A114012.
%K A114011 base,nonn
%O A114011 4,1
%A A114011 _Amarnath Murthy_, Nov 12 2005
%E A114011 More terms from _Robert G. Wilson v_, Nov 17 2005