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 A375048 #4 Sep 20 2024 06:09:06 %S A375048 0,1,1,2,1,2,5,4,1,16,32,24,8,1,162,297,216,78,14,1,3600,5640,3649, %T A375048 1248,238,24,1,147456,196608,110848,34240,6256,676,40,1,12320100, %U A375048 13667940,6521589,1746426,286843,29568,1867,66,1,2058386904,1878686460,746158770 %N A375048 Irregular triangular array T; row n shows the coefficients of the (n-1)-st polynomial in the obverse convolution s(x)**t(x), where s(x) = x+F(n) and t(x) = F(n), where F(n) = n-th Fibonacci number (A000045). See Comments. %C A375048 See A374848 for the definition of obverse convolution and a guide to related sequences and arrays. %e A375048 First 3 polynomials in s(x)**t(x) are %e A375048 0 + x, %e A375048 1 + 2 x + x^2, %e A375048 2 + 4 x + 4 x^2 + x^3. %e A375048 First 5 rows of array: %e A375048 0 1 %e A375048 1 2 1 %e A375048 2 5 4 1 %e A375048 16 32 24 8 1 %e A375048 162 297 216 78 14 1 %t A375048 s[n_] := x + Fibonacci[n]; t[n_] := Fibonacci[n]; %t A375048 u[n_] := Product[s[k] + t[n - k], {k, 0, n}] %t A375048 Table[Expand[u[n]], {n, 0, 10}] %t A375048 Column[Table[CoefficientList[Expand[u[n]], x], {n, 0, 10}]] (* array *) %t A375048 Flatten[Table[CoefficientList[Expand[u[n]], x], {n, 0, 10}]] (* sequence *) %Y A375048 Cf. A000045, A019274 (T(n,n)), A374848, A375047, A375049. %K A375048 nonn,tabf %O A375048 1,4 %A A375048 _Clark Kimberling_, Sep 15 2024