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 A158810 #4 Jul 22 2025 06:23:15 %S A158810 0,-1,0,-2,-1,-2,3,0,0,0,-4,-1,0,0,-4,5,0,-2,0,-4,0,6,-1,-2,3,-4,5,6, %T A158810 -7,0,0,0,0,0,0,0,-8,-1,0,0,0,0,0,0,-8,9,0,-2,0,0,0,0,0,-8,0,10,-1,-2, %U A158810 3,0,0,0,0,-8,9,10,-11,0,0,0,-4,0,0,0,-8,0,0,0,12,-1,0,0,-4,5,0,0,-8,9,0,0 %N A158810 Coefficients of the differentiated row polynomials of the triangular Hadamard matrices of A158800: p(x,n)=If[n less than or equal to 2^m,Sum[H(2^m)[[k]]*x^(1-k),{k,1,n}],If[n greater than m then m+1]. %C A158810 Row sums are: %C A158810 {0, -1, -2, 0, -4, 0, 0, 0, -8, 0, 0, 0, 0, 0, 0, 0,...}. %C A158810 The absolute values of the row sums are: %C A158810 {0, 1, 2, 6, 4, 10, 12, 28, 8, 18, 20, 44, 24, 52, 56, 120,...}. %C A158810 In a quantum Heisenberg matrix mechanics based on the triangular Hadamards %C A158810 where the H(n) behave like wave functions Phi(n), these polynomials %C A158810 are equivalent to the time dependent differentials: %C A158810 Hamiltonian.Phi(n)=-Hbar*I*dPhi(n)/dt %F A158810 Sum of the k-th row polynomial: %F A158810 p(x,n)=If[n>2^m,Sum[H(2^m)[[k]]*x^(1-k),{k,1,n}]]; %F A158810 t(n,l)=coefficients(p(x,n),x) %e A158810 {0}, %e A158810 {-1}, %e A158810 {0, -2}, %e A158810 {-1, -2, 3}, %e A158810 {0, 0, 0, -4}, %e A158810 {-1, 0, 0, -4, 5}, %e A158810 {0, -2, 0, -4, 0, 6}, %e A158810 {-1, -2, 3, -4, 5, 6, -7}, %e A158810 { 0, 0, 0, 0, 0, 0, 0, -8}, %e A158810 {-1, 0, 0, 0, 0, 0, 0, -8, 9}, %e A158810 {0, -2, 0, 0, 0, 0, 0, -8, 0, 10}, %e A158810 {-1, -2, 3, 0, 0, 0, 0, -8, 9, 10, -11}, %e A158810 {0, 0, 0, -4, 0, 0, 0, -8, 0, 0, 0, 12}, %e A158810 {-1, 0, 0, -4, 5, 0, 0, -8, 9, 0, 0, 12, -13}, %e A158810 {0, -2, 0, -4, 0, 6, 0, -8, 0, 10, 0, 12, 0, -14}, %e A158810 {-1, -2, 3, -4, 5, 6, -7, -8, 9, 10, -11, 12, -13, -14, 15} %t A158810 Clear[HadamardMatrix]; %t A158810 MatrixJoinH[A_, B_] := Transpose[Join[Transpose[A], Transpose[B]]]; %t A158810 KroneckerProduct[M_, N_] := Module[{M1, N1, LM, LN, N2}, %t A158810 M1 = M; %t A158810 N1 = N; %t A158810 LM = Length[M1]; %t A158810 LN = Length[N1]; %t A158810 Do[M1[[i, j]] = M1[[i, j]]N1, {i, 1, LM}, {j, 1, LM}]; %t A158810 Do[M1[[i, 1]] = MatrixJoinH[M1[[i, 1]], M1[[i, j]]], {j, 2, LM}, {i, 1, LM}]; %t A158810 N2 = {}; %t A158810 Do[AppendTo[N2, M1[[i, 1]]], {i, 1, LM}]; %t A158810 N2 = Flatten[N2]; %t A158810 Partition[N2, LM*LN, LM*LN]] %t A158810 HadamardMatrix[2] := {{1, 0}, {1, -1}}; %t A158810 HadamardMatrix[n_] := Module[{m}, m = {{1, 0}, {1, -1}}; KroneckerProduct[m, HadamardMatrix[n/2]]]; %t A158810 M = HadamardMatrix[16]; %t A158810 Table[D[Sum[M[[n]][[m]]*x^(m - 1), {m, 1, n}], {x, 1}], {n, 1, Length[M]}]; %t A158810 Table[CoefficientList[D[Sum[ M[[n]][[m]]*x^(m - 1), {m, 1, n}], {x, 1}], x], {n, 1, Length[M]}]; %t A158810 Flatten[%] %Y A158810 A158800 %K A158810 sign,tabl,uned %O A158810 0,4 %A A158810 _Roger L. Bagula_ and _Gary W. Adamson_, Mar 27 2009