%I #25 Sep 11 2021 03:59:04
%S 1,1,13,43,97,181,301,463,673,937,1261,1651,2113,2653,3277,3991,4801,
%T 5713,6733,7867,9121,10501,12013,13663,15457,17401,19501,21763,24193,
%U 26797,29581,32551,35713,39073,42637,46411,50401,54613,59053,63727
%N a(n) = n^3 - 7*n + 7.
%H G. C. Greubel, <a href="/A106734/b106734.txt">Table of n, a(n) for n = 1..1000</a>
%H <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1).
%F n*a(n) + n*(n-1)*7 = n^4.
%F G.f.: (1 - 3*x + 15*x^2 - 7*x^3)/(1-x)^4. - _Harvey P. Dale_, Feb 18 2018
%F E.g.f.: (7 - 6*x + 3*x^2 + x^3)*exp(x) - 7. - _G. C. Greubel_, Sep 11 2021
%e a(2) = 1, 1 + 15 = 2^4;
%e a(3) = 13, 13 + 27 + 41 = 3^4;
%e a(4) = 43, 43 + 57 + 71 + 85 = 4^4.
%t Table[n^3-7n+7,{n,40}] (* or *) LinearRecurrence[{4,-6,4,-1},{1,1,13,43},40] (* _Harvey P. Dale_, Feb 18 2018 *)
%o (PARI) a(n) = n^3 - 7*n + 7; \\ _Michel Marcus_, Sep 05 2013
%o (Sage) [n*(n^2 -7) +7 for n in (0..40)] # _G. C. Greubel_, Sep 11 2021
%Y Cf. A105551.
%K nonn,easy
%O 1,3
%A Andras Erszegi (erszegi.andras(AT)chello.hu), May 14 2005
%E Edited by _N. J. A. Sloane_ at the suggestion of _Andrew S. Plewe_, Jun 16 2007