# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a011893 Showing 1-1 of 1 %I A011893 #28 Oct 10 2024 05:23:09 %S A011893 0,0,0,0,2,5,10,19,30,45,65,90,120,156,198,248,305,370,445,528,621, %T A011893 725,840,966,1104,1254,1418,1595,1786,1993,2214,2451,2705,2976,3264, %U A011893 3570,3894,4238,4601,4984,5389,5814,6261,6731,7224,7740,8280,8844,9434,10049,10690 %N A011893 a(n) = floor( n*(n-1)*(n-2)/11 ). %H A011893 G. C. Greubel, Table of n, a(n) for n = 0..2000 %H A011893 Index entries for linear recurrences with constant coefficients, signature (3,-3,1,0,0,0,0,0,0,0,1,-3,3,-1). %F A011893 a(n) = +3*a(n-1) -3*a(n-2) +a(n-3) +a(n-11) -3*a(n-12) +3*a(n-13) -a(n-14). - _R. J. Mathar_, Apr 15 2010 %F A011893 G.f.: x^4*(2-x+x^2+2*x^3-2*x^4+2*x^5+x^6+x^9)/((1-x)^4*(1+x+x^2+x^3+x^4+x^5 +x^6+x^7+x^8+x^9+x^10)). - _Peter J. C. Moses_, Jun 02 2014 %t A011893 Table[Floor[n(n-1)(n-2)/11],{n,0,40}] (* or *) %t A011893 LinearRecurrence[{3,-3,1,0,0,0,0,0,0,0,1,-3,3,-1}, {0,0,0,0,2,5,10,19,30,45, 65,90,120,156}, 50] (* _Harvey P. Dale_, Nov 23 2018 *) %o A011893 (Magma) [Floor(6*Binomial(n,3)/11): n in [0..50]]; // _G. C. Greubel_, Oct 06 2024 %o A011893 (SageMath) [6*binomial(n,3)//11 for n in range(51)] # _G. C. Greubel_, Oct 06 2024 %Y A011893 Cf. A011886. %K A011893 nonn,easy %O A011893 0,5 %A A011893 _N. J. A. Sloane_ %E A011893 a(41) onwards from _G. C. Greubel_, Oct 06 2024 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE