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 A152182 #13 Oct 04 2023 22:25:46 %S A152182 1,21,371,8090,102125,1061609,12108836,198150335,1929504527 %N A152182 The sequence is a lattice filling using the exponential "E" constant digits base ten. %t A152182 f[ 0 ] := 1; f[ n_Integer /; n > 0 ] := Module[ {i, cnt, m, p}, i = 0; cnt = 0; m = Table[ 0, {10^n} ]; p = Map[ FromDigits, Partition[ First[ RealDigits[ E, 10, 20*10^ n ] ], n, 1 ] ] + 1; Catch[ Map[ ( i++; If[ m[ [ # ] ] == 0, m[ [ # ] ] = 1; If[ ++cnt == 10^n, Throw[ i ] ] ]) &, p ] ] ]; %t A152182 Table[ f[ n ], {n, 0, 5} ] %Y A152182 Cf. A001113. %K A152182 nonn,uned,base %O A152182 0,2 %A A152182 _Roger L. Bagula_, Nov 28 2008, extended Nov 30 2008, Nov 30 2008 %E A152182 a(6)-a(8) from _Michael S. Branicky_, Oct 04 2023