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 A137298 #3 Mar 30 2012 17:34:25 %S A137298 1,0,1,-1,0,1,0,-2,0,1,2,0,-4,0,1,0,6,0,-6,0,1,-6,0,18,0,-9,0,1,0,-30, %T A137298 0,42,0,-13,0,1,30,0,-120,0,87,0,-18,0,1,0,240,0,-414,0,178,0,-25,0,1, %U A137298 -270,0,1320,0,-1197,0,340,0,-34,0,1 %N A137298 Triangle read by rows: coefficients of a Hermite-like set of recursive polynomials that appear by integration to be orthogonal using the substitution on the Hermite recursion of n->f(n) where f(n)=A000931[n] is the Padovan sequence. %C A137298 The number-like behavior of the Padovan sequence made me think that I might get a orthogonal polynomial set by this substitution: %C A137298 Table[Integrate[Exp[ -x2/2]*P[x,n]*P[x, n + 1], {x, -Infinity, Infinity}], {n, 0, 10}]; %C A137298 {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; %C A137298 The row sums are: %C A137298 Table[Apply[Plus, CoefficientList[P[x, n], x]], {n, 0, 10}]; %C A137298 {1, 1, 0, -1, -1, 1, 4, 0, -20, -20, 160} %C A137298 The tiling property of the Fibonacci and Padovan sequences makes me think that other sequence of fundamental number theory "beta Integer-like" sequences might give orthogonal polynomials as well. %F A137298 a(n) = a(n-2)+a(n-3): A000931(n); p(x,0)=1;p(x,1)=x; p(x,n)=x*p(x,n-1)-a(n)*p(n,n-2) %e A137298 {1}, %e A137298 {0, 1}, %e A137298 {-1, 0, 1}, %e A137298 {0, -2, 0, 1}, %e A137298 {2, 0, -4, 0, 1}, %e A137298 {0, 6, 0, -6, 0, 1}, %e A137298 {-6, 0, 18, 0, -9, 0, 1}, %e A137298 {0, -30, 0, 42, 0, -13, 0, 1}, %e A137298 {30, 0, -120, 0, 87, 0, -18, 0, 1}, %e A137298 {0, 240, 0, -414, 0, 178, 0, -25, 0, 1}, %e A137298 {-270, 0, 1320, 0, -1197, 0, 340, 0, -34, 0, 1} %t A137298 f[0] = 0; f[1] = 1;f[2]=1; f[n_] := f[n] = f[n - 2] + f[n - 3]; P[x, 0] = 1; P[x, 1] = x; P[x_, n_] := P[x, n] = x*P[x, n - 1] - f[n]*P[x, n - 2]; Table[ExpandAll[P[x, n]], {n, 0, 10}]; a = Table[CoefficientList[P[x, n], x], {n, 0, 10}] Flatten[a] %Y A137298 Cf. A000045, A000931. %K A137298 uned,tabl,sign %O A137298 1,8 %A A137298 _Roger L. Bagula_, Mar 14 2008