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 A379372 #9 Dec 23 2024 02:17:09
%S A379372 322,357,370,402,430,442,610,654,790,822,826,874,885,942,1045,1054,
%T A379372 1105,1130,1182,1222,1342,1358,1414,1510,1578,1582,1677,1702,1738,
%U A379372 1742,1767,1798,1802,1810,1842,1947,2014,2035,2086,2185,2222,2247,2282,2334,2365,2397
%N A379372 Sphenic numbers k such that 2*k+1 is also a sphenic number.
%e A379372 322 is a term because 322 = 2*7*23 (sphenic) and 2*322+1 = 645 = 3*5*43 (sphenic).
%t A379372 sphenicQ[n_] := FactorInteger[n][[;; , 2]] == {1, 1, 1}; Select[Range[3000], And @@ sphenicQ /@ {#, 2*# + 1} &] (* _Amiram Eldar_, Dec 21 2024 *)
%Y A379372 Cf. A007304, A177221.
%K A379372 nonn,easy
%O A379372 1,1
%A A379372 _Paul Duckett_, Dec 21 2024