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 A117881 #10 Apr 05 2025 10:43:38
%S A117881 4,4,10,33,106,309,965,3022,9489,29813,93649,294209,924271,2903678,
%T A117881 9122173,28658147,90032221,282844574,888582413,2791563955,8769956797,
%U A117881 27551631845,86556004193,271923706897,854273519921,2683779414319
%N A117881 First semiprime after Pi^n.
%C A117881 Pi and semiprime analog of A074496 First prime after e^n. Lim_{n->infinity} a(n+1)/a(n) = Pi. See also A000796 Decimal expansion of Pi. There are numbers where floor(Pi^n) is itself a semiprime, as with floor(Pi^2) = 9, floor(Pi^6) = 961 = 31^2, floor(Pi^9) = 29809 = 13 * 2293, floor(Pi^25) = 2683779414317 = 5749 * 466825433.
%H A117881 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/e-Prime.html">e-Prime.</a>
%F A117881 a(n) = min{s in A001358 and s > Pi^n}.
%e A117881 a(3) = 33 because Pi^3 = 31.0062766... floor(Pi^3) = 31 is prime hence 31 + 2 = 33 is a term.
%t A117881 fsp[n_]:=Module[{k=Ceiling[Pi^n]},While[PrimeOmega[k]!=2,k++];k]; Array[fsp,30,0]
%Y A117881 Cf. A000040, A000149, A000796, A001358, A007512, A014210, A050808, A050809, A059303, A064118, A095935, A115019, A074496, A118840.
%K A117881 easy,nonn
%O A117881 0,1
%A A117881 _Jonathan Vos Post_, May 02 2006