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 A011937 #19 Oct 29 2024 03:43:19
%S A011937 0,0,0,0,0,4,13,31,62,112,186,293,440,635,889,1213,1617,2115,2720,
%T A011937 3445,4306,5320,6502,7871,9445,11244,13288,15600,18200,21112,24360,
%U A011937 27968,31964,36373,41223,46542,52360,58706,65613,73112,81235,90017,99493,109697,120667,132440,145053,158546,172960,188334
%N A011937 a(n) = floor( n*(n-1)*(n-2)*(n-3)/27 ).
%H A011937 G. C. Greubel, <a href="/A011937/b011937.txt">Table of n, a(n) for n = 0..2500</a>
%H A011937 <a href="/index/Rec#order_31">Index entries for linear recurrences with constant coefficients</a>, signature (4,-6,4,-1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,-4,6,-4,1).
%F A011937 From _Chai Wah Wu_, Aug 02 2020: (Start)
%F A011937 a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) + a(n-27) - 4*a(n-28) + 6*a(n-29) - 4*a(n-30) + a(n-31) for n > 30.
%F A011937 G.f.: x^5*(4 -3*x +3*x^2 +2*x^4 -x^5 +4*x^6 -2*x^7 +x^8 +3*x^9 -x^11 +4*x^12 -x^13 +3*x^15 +x^16 -2*x^17 +4*x^18 -x^19 +2*x^20 +3*x^22 -3*x^23 +4*x^24)/((1-x)^5*(1 +x +x^2)*(1 +x^3 +x^6)*(1 +x^9 +x^18)). (End)
%t A011937 Table[Floor[n (n-1)(n-2)(n-3)/27], {n, 0, 60}] (* _Wesley Ivan Hurt_, Jan 02 2024 *)
%o A011937 (PARI) a(n)=n*(n-1)*(n-2)*(n-3)\27 \\ _Charles R Greathouse IV_, Oct 18 2022
%o A011937 (Magma) [Floor(8*Binomial(n,4)/9): n in [0..80]]; // _G. C. Greubel_, Oct 29 2024
%o A011937 (SageMath) [8*binomial(n,4)//9 for n in range(81)] # _G. C. Greubel_, Oct 29 2024
%Y A011937 Cf. A011915.
%K A011937 nonn,easy
%O A011937 0,6
%A A011937 _N. J. A. Sloane_
%E A011937 More terms added by _G. C. Greubel_, Oct 29 2024