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 A277240 #9 May 21 2024 13:10:28
%S A277240 1,2,9,27,74,168,363,703,1297,2247,3742,5967,9241,13859,20307,29052,
%T A277240 40786,56187,76233,101858,134377,175068,225640,287772,363673,455482,
%U A277240 565977,697875,854594,1039500,1256787,1510547,1805833,2147607,2541870,2994543,3512737
%N A277240 Number of factorizations of m^n into exactly four factors, where m is a product of two distinct primes.
%H A277240 Alois P. Heinz, <a href="/A277240/b277240.txt">Table of n, a(n) for n = 0..10000</a>
%H A277240 <a href="/index/Rec#order_16">Index entries for linear recurrences with constant coefficients</a>, signature (2,1,-2,-2,-2,5,2,0,-2,-5,2,2,2,-1,-2,1)
%F A277240 G.f.: -(x^12 +4*x^10 +9*x^9 +17*x^8 +17*x^7 +24*x^6 +17*x^5 +17*x^4 +9*x^3 +4*x^2 +1) / ((x^2+1) *(x^2+x+1)^2 *(x+1)^3 *(x-1)^7).
%e A277240 a(2) = 9: (2*3)^2 = 2*2*3*3 = 1*3*3*4 = 1*2*3*6 = 1*2*2*9 = 1*1*4*9 = 1*1*6*6 = 1*1*2*18 = 1*1*3*12 = 1*1*1*36.
%t A277240 LinearRecurrence[{2,1,-2,-2,-2,5,2,0,-2,-5,2,2,2,-1,-2,1},{1,2,9,27,74,168,363,703,1297,2247,3742,5967,9241,13859,20307,29052},40] (* _Harvey P. Dale_, May 21 2024 *)
%Y A277240 Column k=4 of A277239.
%K A277240 nonn
%O A277240 0,2
%A A277240 _Alois P. Heinz_, Oct 06 2016