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 A060189 #28 Aug 01 2024 01:52:54
%S A060189 1,23,230,1682,10543,60657,331612,1756340,9116141,46702427,237231970,
%T A060189 1198382694,6031771195,30287995733,151856096504,760614930344,
%U A060189 3807336276505,19050241098975,95294209168414,476607030432890
%N A060189 A column and diagonal of A060187 (k=3).
%H A060189 G. C. Greubel, <a href="/A060189/b060189.txt">Table of n, a(n) for n = 3..1000</a>
%H A060189 P. A. MacMahon, <a href="http://plms.oxfordjournals.org/content/s2-19/1/305.extract">The divisors of numbers</a>, Proc. London Math. Soc., (2) 19 (1920), 305-340; Coll. Papers II, pp. 267-302.
%H A060189 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (14,-75,196,-263,174,-45).
%F A060189 a(n) = 5^(n-1) - n*3^(n-1) + n*(n-1)/2. - _Ralf Stephan_, May 08 2004
%F A060189 G.f.: x^3*(1 + 9*x - 17*x^2 - 9*x^3) / ((1-x)^3*(1-3*x)^2*(1-5*x)). - _Colin Barker_, Dec 19 2012
%F A060189 From _Wolfdieter Lang_, Apr 17 2017: (Start)
%F A060189 a(n) = A060187(n, 3) , n >= 3 (and 0 for n = 0,1,2).
%F A060189 a(n) = A060187(n, n-2), n >= 3 (and 0 for n = 0,1,2).
%F A060189 E.g.f.: (2*exp(5*x) - 10*x*exp(3*x) + 5*x^2*exp(x) - 2)/10. (End)
%t A060189 Table[5^(n-1) -n*3^(n-1) +n*(n-1)/2, {n,3,40}] (* _G. C. Greubel_, Jul 31 2024 *)
%o A060189 (Magma)
%o A060189 [5^(n-1) -n*3^(n-1) +n*(n-1)/2: n in [3..40]]; // _G. C. Greubel_, Jul 31 2024
%o A060189 (SageMath)
%o A060189 [5^(n-1) -n*3^(n-1) +n*(n-1)//2 for n in range(3,41)] # _G. C. Greubel_, Jul 31 2024
%Y A060189 Cf. A060187.
%K A060189 nonn,easy
%O A060189 3,2
%A A060189 _N. J. A. Sloane_, Mar 20 2001
%E A060189 More terms from _Vladeta Jovovic_, Mar 20 2001