# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a114211 Showing 1-1 of 1 %I A114211 #14 Jun 13 2015 00:52:02 %S A114211 1,4,16,42,87,156,254,386,557,772,1036,1354,1731,2172,2682,3266,3929, %T A114211 4676,5512,6442,7471,8604,9846,11202,12677,14276,16004,17866,19867, %U A114211 22012,24306,26754,29361,32132,35072,38186,41479 %N A114211 a(n) = (5*n^3+12*n^2+n+6)/6. %C A114211 Column 3 of A114202. Third differences are 1,1,7,5,5,5,5,5,... with g.f. (1+6x^2-2x^3)/(1-x). %H A114211 Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1). %F A114211 G.f.: (1+6*x^2-2*x^3)/(1-x)^4 = (1+3*(x/(1-x))+9*(x/(1-x))^2+5*(x/(1-x))^3)/(1-x). %F A114211 a(n) = sum{k=0..n, C(n, k)*C(3, k)*J(k+1)} where J(n)=A001045(n). %F A114211 a(0)=1, a(n)=a(n-1)+(n-1)*(n+2)+A104249(n). %e A114211 [1,3,9,5]=[1*1,3*1,3*3,1*5]=[C(3,0)*J(1),C(3,1)*J(2),C(3,2)*J(3),C(3,3)*J(4)]. %t A114211 CoefficientList[Series[(1+6x^2-2x^3)/(1-x)^4,{x,0,75}],x] (* _Harvey P. Dale_, Mar 06 2011 *) %K A114211 easy,nonn %O A114211 0,2 %A A114211 _Paul Barry_, Nov 17 2005 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE