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 A081854 #15 Jun 26 2024 12:18:15
%S A081854 3,60,2093,13398,47415,123728,268065,512298,894443,1458660,2255253,
%T A081854 3340670,4777503,6634488,8986505,11914578,15505875,19853708,25057533,
%U A081854 31222950,38461703,46891680,56636913,67827578,80599995,95096628,111466085,129863118,150448623
%N A081854 a(n) = (8*n - 3)*(4*n - 1)*(8*n^2 - 5*n + 1).
%H A081854 J. C. Lagarias and N. J. A. Sloane, Approximate squaring (<a href="http://neilsloane.com/doc/apsq.pdf">pdf</a>, <a href="http://neilsloane.com/doc/apsq.ps">ps</a>), Experimental Math., 13 (2004), 113-128.
%H A081854 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (5,-10,10,-5,1).
%F A081854 G.f.: (60 + 1793*x + 3533*x^2 + 755*x^3 + 3*x^4)/(1-x)^5.
%F A081854 a(0)=3, a(1)=60, a(2)=2093, a(3)=13398, a(4)=47415, a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5). - _Harvey P. Dale_, Mar 20 2015
%F A081854 E.g.f.: exp(x)*(3 + 57*x + 988*x^2 + 1216*x^3 + 256*x^4). - _Stefano Spezia_, Jun 26 2024
%t A081854 Table[(8n-3)(4n-1)(8n^2-5n+1),{n,0,30}] (* or *) LinearRecurrence[{5,-10,10,-5,1},{3,60,2093,13398,47415},30] (* _Harvey P. Dale_, Mar 20 2015 *)
%o A081854 (PARI) a(n)=(8*n-3)*(4*n-1)*(8*n^2-5*n+1) \\ _Charles R Greathouse IV_, Oct 21 2022
%Y A081854 Value of A081853 when started at b(0) with 2*b(0) == 5 (mod 8).
%K A081854 nonn,easy
%O A081854 0,1
%A A081854 _N. J. A. Sloane_, Apr 13 2003