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 A208762 #12 Aug 12 2015 04:02:32 %S A208762 1,2,2,3,7,4,4,17,21,8,5,34,68,55,16,6,60,174,225,137,32,7,97,384,705, %T A208762 674,327,64,8,147,763,1863,2489,1883,761,128,9,212,1400,4362,7640, %U A208762 8012,5016,1735,256,10,294,2412,9318,20542,27996,24144,12885,3897 %N A208762 Triangle of coefficients of polynomials v(n,x) jointly generated with A208761; see the Formula section. %C A208762 Alternating row sums: 1,0,0,0,0,0,0,0,0,... For a discussion and guide to related arrays, see A208510. %C A208762 As triangle T(n,k) with 0<=k<=n, it is (2, -1/2, 1/2, 0 0 0 0 0 0 0 ...) DELTA (2, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, ...) where DELTA is the operator defined in A084938. - _Philippe Deléham_, Mar 04 2012 %C A208762 Row sums are in A055099. - _Philippe Deléham_, Mar 04 2012 %F A208762 u(n,x)=u(n-1,x)+2x*v(n-1,x), %F A208762 v(n,x)=(x+1)*u(n-1,x)+(x+1)*v(n-1,x), %F A208762 where u(1,x)=1, v(1,x)=1. %F A208762 As triangle T(n,k) with 0<=k<=n : T(n,k) = 2*T(n-1,k) + T(n-1,k-1) - T(n-2,k) + T(n-2,k-1) + 2*T(n-2,k-2), T(0,0) = 1, T(1,0) = T(1,1) = 2 and T(n,k) = 0 if k>n or if k<0. - _Philippe Deléham_, Mar 04 2012 %F A208762 G.f.: (-1-x*y)*x*y/(-1+x*y+x^2*y+2*x^2*y^2+2*x-x^2). - _R. J. Mathar_, Aug 12 2015 %e A208762 First five rows: %e A208762 1 %e A208762 2...2 %e A208762 3...7....4 %e A208762 4...17...21...8 %e A208762 5...34...68...55...16 %e A208762 First five polynomials v(n,x): %e A208762 1 %e A208762 2 + 2x %e A208762 3 + 7x + 4x^2 %e A208762 4 + 17x + 22x^2 + 8x^3 %e A208762 5 + 34x + 68x^2 + 55x^3 + 16x^4 %t A208762 u[1, x_] := 1; v[1, x_] := 1; z = 16; %t A208762 u[n_, x_] := u[n - 1, x] + 2 x*v[n - 1, x]; %t A208762 v[n_, x_] := (x + 1)*u[n - 1, x] + (x + 1) v[n - 1, x]; %t A208762 Table[Expand[u[n, x]], {n, 1, z/2}] %t A208762 Table[Expand[v[n, x]], {n, 1, z/2}] %t A208762 cu = Table[CoefficientList[u[n, x], x], {n, 1, z}]; %t A208762 TableForm[cu] %t A208762 Flatten[%] (* A208761 *) %t A208762 Table[Expand[v[n, x]], {n, 1, z}] %t A208762 cv = Table[CoefficientList[v[n, x], x], {n, 1, z}]; %t A208762 TableForm[cv] %t A208762 Flatten[%] (* A208762 *) %Y A208762 Cf. A208761, A208510. %K A208762 nonn,tabl %O A208762 1,2 %A A208762 _Clark Kimberling_, Mar 03 2012