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 A177223 #15 Jan 11 2025 15:56:50
%S A177223 145,203,291,298,407,497,649,707,758,815,899,926,959,995,1079,1094,
%T A177223 1139,1142,1157,1313,1403,1415,1461,1497,1538,1639,1658,1691,1857,
%U A177223 1934,1945,1991,2123,2159,2217,2234,2315,2603,2629,2807,2991,3215,3254,3279,3305
%N A177223 Numbers k that are the products of two distinct primes such that 2*k+1, 4*k+3 and 8*k+7 are also products of two distinct primes.
%C A177223 A number k is the product of two distinct primes iff k = p*q where p and q are distinct primes. - _N. J. A. Sloane_, Jan 11 2025
%H A177223 Harvey P. Dale, <a href="/A177223/b177223.txt">Table of n, a(n) for n = 1..1000</a>
%e A177223 145 is a term because 145 = 5*29, 2*145 + 1 = 291 = 3*97, 4*145 + 1 = 583 = 11*53, and 8*145 + 1 = 1167 = 3*389.
%t A177223 f[n_]:=Last/@FactorInteger[n]=={1,1}; lst={};Do[If[f[n]&&f[2*n+1]&&f[4*n+3]&&f[8*n+7],AppendTo[lst,n]],{n,0,2*7!}];lst
%t A177223 tdpQ[n_]:=With[{c={n, 2n+1, 4n+3,8n+7}},PrimeNu[c]==PrimeOmega[c]=={2,2,2,2}]; Select[Range[3500],tdpQ] (* _Harvey P. Dale_, Jan 11 2025 *)
%Y A177223 Cf. A006881, A111153, A177210, A177211, A177212, A177213, A177214, A177215, A177216, A177217, A177220, A177221, A177222.
%K A177223 nonn
%O A177223 1,1
%A A177223 _Vladimir Joseph Stephan Orlovsky_, May 05 2010