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 A007752 #23 Jul 04 2024 14:33:15
%S A007752 1,24,391,6240,99457,1585080,25261831,402604224,6416405761,
%T A007752 102259887960,1629741801607,25973608937760,413948001202561,
%U A007752 6597194410303224,105141162563649031,1675661406608081280
%N A007752 Odd bisection of A007750.
%D A007752 Mentioned in a problem on p. 334 of Two-Year College Math. Jnl., Vol. 25, 1994.
%H A007752 G. C. Greubel, <a href="/A007752/b007752.txt">Table of n, a(n) for n = 1..825</a>
%H A007752 K. R. S. Sastry, <a href="https://www.jstor.org/stable/2687624">Problem 533</a> The College Mathematics Journal, 25, issue 4, 1994, p. 334.
%H A007752 K. R. S. Sastry, <a href="https://www.jstor.org/stable/2687039">Square Products of Sums of Squares</a> The College Mathematics Journal, 26, issue 4, 1995, p. 333.
%H A007752 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (17,-17,-1).
%F A007752 G.f.: x*(1+7*x)/((1-x)*(1-16*x+x^2)).
%F A007752 a(n) = 16*a(n-1) - a(n-2) + 8.
%F A007752 a(n) = (4*ChebyshevU(n, 8) -53*ChebyshevU(n-1, 8) -4)/7. - _G. C. Greubel_, Mar 04 2020
%F A007752 E.g.f.: (exp(8*x)*(4*cosh(3*sqrt(7)*x) - sqrt(7)*sinh(3*sqrt(7)*x)) - 4*exp(x))/7. - _Stefano Spezia_, Mar 14 2020
%F A007752 a(n) = A097830(n-1)+7*A097830(n-2). - _R. J. Mathar_, Jul 04 2024
%p A007752 seq( simplify( (4*ChebyshevU(n,8) - 53*ChebyshevU(n-1,8) -4)/7), n=1..20); # _G. C. Greubel_, Mar 04 2020
%t A007752 Table[(4*ChebyshevU[n, 8] -53*ChebyshevU[n-1, 8] -4)/7, {n,20}] (* _G. C. Greubel_, Mar 04 2020 *)
%o A007752 (PARI) a(n)=local(w); w=8+3*quadgen(28); imag(1/w^n)+4*(real(1/w^n)-1)/7
%o A007752 (PARI) vector(30, n, (4*polchebyshev(n,2,8) -53*polchebyshev(n-1,2,8) -4)/7 ) \\ _G. C. Greubel_, Mar 04 2020
%o A007752 (Magma) I:=[1,24,391]; [n le 3 select I[n] else 17*Self(n-1) -17*Self(n-2) +Self(n-3): n in [1..30]]; // _G. C. Greubel_, Mar 04 2020
%o A007752 (Sage) [(4*chebyshev_U(n,8) -53*chebyshev_U(n-1,8) -4)/7 for n in (1..30)] # _G. C. Greubel_, Mar 04 2020
%o A007752 (GAP) a:=[1,24,391];; for n in [4..30] do a[n]:=17*a[n-1]-17*a[n-2]+a[n-3]; od; a; # _G. C. Greubel_, Mar 04 2020
%Y A007752 Cf. A007750, A007751.
%K A007752 nonn,easy
%O A007752 1,2
%A A007752 John C. Hallyburton, Jr. (hallyb(AT)vmsdev.enet.dec.com)
%E A007752 Edited by _Michael Somos_, Jul 27 2002