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 A210755 #6 Mar 30 2012 18:58:17 %S A210755 1,2,3,3,11,7,4,26,38,17,5,50,124,121,41,6,85,314,499,362,99,7,133, %T A210755 679,1555,1805,1043,239,8,196,1316,4054,6672,6096,2926,577,9,276,2352, %U A210755 9318,20326,26048,19610,8049,1393,10,375,3948,19482,53932,90706 %N A210755 Triangle of coefficients of polynomials u(n,x) jointly generated with A210756; see the Formula section. %C A210755 Row n starts with n and ends with A001333(n). %C A210755 Column 2: A051925 %C A210755 Row sums: A002450 %C A210755 Alternating row sums: 1,-1,-1,-1,-1,-1,... %C A210755 For a discussion and guide to related arrays, see A208510. %F A210755 u(n,x)=(x+1)*u(n-1,x)+2x*v(n-1,x)+1, %F A210755 v(n,x)=(x+1)*u(n-1,x)+(x+1)*v(n-1,x)+1, %F A210755 where u(1,x)=1, v(1,x)=1. %e A210755 First five rows: %e A210755 1 %e A210755 2...3 %e A210755 3...11...7 %e A210755 4...26...38....17 %e A210755 5...50...124...121...41 %e A210755 First three polynomials u(n,x): 1, 2 + 3x, 3 + 11x + 7x^2. %t A210755 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A210755 u[n_, x_] := (x + 1)*u[n - 1, x] + 2 x*v[n - 1, x] + 1; %t A210755 v[n_, x_] := (x + 1)*u[n - 1, x] + (x + 1)*v[n - 1, x] + 1; %t A210755 Table[Expand[u[n, x]], {n, 1, z/2}] %t A210755 Table[Expand[v[n, x]], {n, 1, z/2}] %t A210755 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A210755 TableForm[cu] %t A210755 Flatten[%] (* A210755 *) %t A210755 Table[Expand[v[n, x]], {n, 1, z}] %t A210755 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A210755 TableForm[cv] %t A210755 Flatten[%] (* A210756 *) %t A210755 Table[u[n, x] /. x -> 1, {n, 1, z}] (* A002450 *) %t A210755 Table[v[n, x] /. x -> 1, {n, 1, z}] (* A002450 *) %Y A210755 Cf. A210754, A208510. %K A210755 nonn,tabl %O A210755 1,2 %A A210755 _Clark Kimberling_, Mar 25 2012