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 A214092 #25 Jun 17 2017 02:59:45
%S A214092 1,23,102,274,575,1041,1708,2612,3789,5275,7106,9318,11947,15029,
%T A214092 18600,22696,27353,32607,38494,45050,52311,60313,69092,78684,89125,
%U A214092 100451,112698,125902,140099,155325,171616
%N A214092 Principal diagonal of the convolution array A213773.
%H A214092 Clark Kimberling, <a href="/A214092/b214092.txt">Table of n, a(n) for n = 1..999</a>
%H A214092 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F A214092 a(n) = (5*n - 15*n^2 + 12*n^3)/2.
%F A214092 a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4).
%F A214092 G.f.: f(x)/g(x), where f(x) = x*(1 + 19*x + 16*x^2) and g(x) = (1-x)^4.
%t A214092 (See A213773.)
%t A214092 LinearRecurrence[{4,-6,4,-1},{1,23,102,274},40] (* _Harvey P. Dale_, Nov 20 2015 *)
%Y A214092 Cf. A213773.
%Y A214092 Cf. A260260 (comment). [_Bruno Berselli_, Jul 22 2015]
%K A214092 nonn,easy
%O A214092 1,2
%A A214092 _Clark Kimberling_, Jul 04 2012