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 A117879 #11 Feb 16 2025 08:33:00
%S A117879 4,4,9,21,55,155,407,1099,2981,8105,22033,59881,162757,442417,1202611,
%T A117879 3269021,8886117,24154953,65659981,178482301,485165203,1318815739,
%U A117879 3584912849,9744803447,26489122131,72004899341,195729609431
%N A117879 First semiprime after e^n.
%C A117879 Semiprime analog of A074496 = first prime after e^n. Lim_{n->infinity} a(n+1)/a(n) = e. There are numbers where floor(e^n) is itself a semiprime, as with floor(e^6) = 403 = 13 * 31, floor(e^15) = 3269017 = 773 * 4229, floor(e^20) = 485165195 = 5 * 97033039, floor(e^22) = 3584912846 = 2 * 1792456423, floor(e^24) = 26489122129 = 103 * 257175943.
%H A117879 Harvey P. Dale, <a href="/A117879/b117879.txt">Table of n, a(n) for n = 0..100</a>
%H A117879 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/e-Prime.html">e-Prime.</a>
%F A117879 a(n) = Smallest semiprime > e^n. Smallest semiprime > floor(e^n). a(n) = min{s > A000149(n) and s in A001358}.
%t A117879 fsa[n_]:=Module[{i=1,c=Floor[E^n]},While[PrimeOmega[c+i]!=2,i++];c+i]; Array[fsa,30,0] (* _Harvey P. Dale_, Oct 18 2013 *)
%Y A117879 Cf. A000040, A000149, A001358, A007512, A014210, A050808, A050809, A059303, A064118, A095935, A115019, A074496, A118840.
%K A117879 easy,nonn,less
%O A117879 0,1
%A A117879 _Jonathan Vos Post_, May 02 2006