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%I #17 Oct 19 2022 07:49:04
%S 1,4,10,20,36,60,94,140,200,276,370,484,620,780,966,1180,1424,1700,
%T 2010,2356,2740,3164,3630,4140,4696,5300,5954,6660,7420,8236,9110,
%U 10044,11040,12100,13226,14420
%N Binomial transform of [1, 3, 3, 1, 1, -1, 1, -1, 1, ...].
%H E. Hetmaniok, M. Pleszczynski, I. Sobstyl, R. Witula, <a href="https://annals-csis.org/proceedings/2015/pliks/15.pdf">Kaprekar's transformations. Part II-numerical results and intriguing corollaries</a>, Position Papers of the Federated Conference on Computer Science and Information Systems pp. 97-104, ACSIS, Vol. 6; DOI: 10.15439/2015F15.
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F A007318 * [1, 3, 3, 1, 1, -1, 1, -1, 1, ...].
%F From _Emeric Deutsch_, Jun 03 2008: (Start)
%F a(n) = n*(11 + n^2)/3 for n >= 1.
%F G.f.: (1+x^4)/(1-x)^4. (End)
%e a(5) = 36 = (1, 4, 6, 4, 1) dot (1, 3, 3, 1, 1) = (1 + 12 + 18 + 4 + 1).
%p 1, seq((1/3)*n*(11+n^2),n=1..35); # _Emeric Deutsch_, Jun 03 2008
%t CoefficientList[Series[(1+x^4)/(1-x)^4,{x,0,50}],x] (* or *) LinearRecurrence[{4,-6,4,-1},{1,4,10,20,36},50] (* _Harvey P. Dale_, Aug 17 2021 *)
%o (PARI) a(n)=max(n*(11 + n^2)/3,1) \\ _Charles R Greathouse IV_, Oct 19 2022
%K nonn,easy
%O 0,2
%A _Gary W. Adamson_, May 12 2008
%E More terms from _Emeric Deutsch_, Jun 03 2008
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