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 A337881 #11 Oct 17 2020 05:46:41 %S A337881 1,2,6,8,16,48,96,432,384,512,2304,4608,23040,8192,24576,49152,65536, %T A337881 294912,655360,1310720,2621440,10616832,6291456,28311552,62914560, %U A337881 75497472,251658240,838860800,402653184,805306368,1073741824,12079595520,14495514624,65229815808 %N A337881 30*a(n) - 1 is the least prime of the form 2^r*3^s*5^t - 1, r > 0, s > 0, t > 0, r + s + t = n. %H A337881 Hugo Pfoertner, <a href="/A337881/b337881.txt">Table of n, a(n) for n = 3..1000</a> %Y A337881 Cf. A051037, A071520, A336773, A337882. %K A337881 nonn %O A337881 3,2 %A A337881 _Hugo Pfoertner_ and _Rainer Rosenthal_, Oct 12 2020