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 A346138 #23 Aug 17 2021 07:29:58
%S A346138 651,2667,11811,27559,172011,761763,1777447,2752491,3120771,7281799,
%T A346138 11010027,12189603,28442407,32247967,48758691,49938051,113770279,
%U A346138 116522119,199753347,466091143,516026527,2064117919,3220807683,7515217927,12883304451,30061043719,33281679391,45097156587,133127479327
%N A346138 Sphenic numbers that are the product of Mersenne primes.
%C A346138 The largest known sphenic number is a term of this sequence.
%C A346138 a(n) == 3 (mod 4) for n >= 1.
%H A346138 Wikipedia, <a href="https://en.wikipedia.org/wiki/Sphenic_number">Sphenic number</a> (lists the largest known sphenic number)
%H A346138 Wikipedia, <a href="https://en.wikipedia.org/wiki/Mersenne_prime">Mersenne prime</a>
%H A346138 <a href="/index/Pri#prime_signature">Index to sequences related to prime signature</a>
%e A346138 a(1) = 651, since 651 = 3*7*31.
%e A346138 a(2) = 2667, since 2667 = 3*7*127.
%e A346138 a(3) = 11811, since 11811 = 3*31*127.
%t A346138 M = 2^MersennePrimeExponent[Range[12]] - 1; Take[ Union[ Times @@@ Subsets[ M, {3}]], 50]
%Y A346138 Cf. A007304, A046528, A144856.
%K A346138 nonn
%O A346138 1,1
%A A346138 _Timothy L. Tiffin_, Jul 06 2021