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 A006090 #21 Jan 05 2025 19:51:33
%S A006090 1,-6,21,-56,126,-252,463,-804,1365,-2366,4368,-8736,18565,-40410,
%T A006090 87381,-184604,379050,-758100,1486675,-2884776,5592405,-10919090,
%U A006090 21572460,-43144920,87087001,-176565486,357913941,-723002336
%N A006090 Expansion of bracket function.
%H A006090 G. C. Greubel, <a href="/A006090/b006090.txt">Table of n, a(n) for n = 0..1000</a>
%H A006090 H. W. Gould, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/2-4/gould.pdf">Binomial coefficients, the bracket function and compositions with relatively prime summands</a>, Fib. Quart. 2, issue 4, (1964), 241-260.
%H A006090 <a href="/A005589/a005589.pdf">Problems Drive</a>, Eureka, 37 (1974), 8-11, 32-33, 24-27. (Annotated scanned copy)
%H A006090 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (-6,-15,-20,-15,-6).
%F A006090 G.f.: 1/((1+x)^6-x^6).
%F A006090 a(n) = (-1)^n * Sum_{k=0..floor(n/6)} binomial(n+5,6*k+5). - _Seiichi Manyama_, Aug 05 2024
%t A006090 CoefficientList[Series[1/((1+x)^6-x^6),{x,0,30}],x] (* or *) LinearRecurrence[ {-6,-15,-20,-15,-6},{1,-6,21,-56,126},31] (* _Harvey P. Dale_, Oct 14 2016 *)
%o A006090 (PARI) x='x+O('x^50); Vec(1/((1+x)^6-x^6)) \\ _G. C. Greubel_, Jul 02 2017
%Y A006090 Column 6 of A307047.
%Y A006090 Cf. A000748, A000749, A000750, A001659.
%K A006090 sign
%O A006090 0,2
%A A006090 _David Callan_