{"id":"n-c7873b474df0d18a","revision":1,"first_index":0,"fingerprint":"f6-6e028b83a8347d20","name":"theta_plus_one_squared of Exponential Riordan array (1, x(1+x/2)).","polytool_family":null,"interpretation":null,"rows_observed":15,"degree_pattern":"affine","degree_slope":1,"degree_intercept":0,"palindromic":0,"gamma_positive":0,"nonnegative":1,"rr_by_factors":false,"rows":[["1"],["0","4"],["0","4","9"],["0","0","27","16"],["0","0","27","96","25"],["0","0","0","240","250","36"],["0","0","0","240","1125","540","49"],["0","0","0","0","2625","3780","1029","64"],["0","0","0","0","2625","15120","10290","1792","81"],["0","0","0","0","0","34020","61740","24192","2916","100"],["0","0","0","0","0","34020","231525","201600","51030","4500","121"],["0","0","0","0","0","0","509355","1108800","561330","99000","6655","144"],["0","0","0","0","0","0","509355","3991680","4209975","1386000","179685","9504","169"],["0","0","0","0","0","0","0","8648640","21891870","13513500","3114540","308880","13182","196"],["0","0","0","0","0","0","0","8648640","76621545","94594500","38153115","6486480","507507","17836","225"]],"degrees":[0,1,2,3,4,5,6,7,8,9,10,11,12,13,14],"row_sums":["1","4","13","43","148","526","1954","7498","29908","122968","522796","2285284","10286368","47490808","225029848"],"nonn":true,"definitions":[{"position":0,"source":"derived:theta_plus_one_squared","source_kind":"derived","equality_edge_id":null,"recurrence":{"first_index":0,"initial_polynomials":[["1"]],"recurrence":{"denominator":{"coeffs":[["4","4","0"],["12","-14","0"],["13","-18","4"],["6","-4","0"],["1","0","0"]]},"terms":[{"coeff":{"coeffs":[["4","20","-28","4"],["8","42","-58","8"],["1","49","-34","4"],["-7","28","-8","0"],["-5","5","0","0"],["-1","0","0","0"]]},"deriv_order":0,"offset":1,"sign":"none"},{"coeff":{"coeffs":[["0","8","-32","8"],["0","24","-68","16"],["0","26","-44","8"],["0","12","-8","0"],["0","2","0","0"]]},"deriv_order":1,"offset":1,"sign":"none"}]},"schema":"polytool.recurrence.v1"}}],"properties":[{"id":163412,"position":0,"claim":"real_rooted","from_index":0,"region_key":"(-inf, 0]","provenance":"edges","claim_data":{"claim":"real_rooted","from_index":0,"region":{"upper":{"closed":true,"value":"0"}}},"label":"Real-rooted","description":"Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]","region_exact":null,"edges":["e-38acf07bf4ec9f74"]},{"id":163413,"position":1,"claim":"one_signed_coefficients","from_index":0,"region_key":null,"provenance":"derived_from_edges","claim_data":{"alternating":false,"claim":"one_signed_coefficients","from_index":0},"label":"Coefficients of one sign","description":"Every nonzero row, n >= 0: the coefficients of P_n have one sign","region_exact":null,"edges":["e-38acf07bf4ec9f74"]},{"id":163414,"position":2,"claim":"hadamard_kernel","from_index":0,"region_key":null,"provenance":"derived_from_edges","claim_data":{"claim":"hadamard_kernel","from_index":0},"label":"Hadamard kernel (Malo)","description":"Rows P_n, n >= 0, are Hadamard kernels (preserve real-rootedness)","region_exact":null,"edges":["e-38acf07bf4ec9f74"]}],"region_exact":{},"incoming_edges":[{"id":"e-38acf07bf4ec9f74","operation":{"index_shift":0,"operation":"preserver_image","operator":"{\"shape\":\"euler_polynomial\",\"coefficients\":[{\"numerator\":[\"1\"],\"denominator\":[\"1\"]},{\"numerator\":[\"2\"],\"denominator\":[\"1\"]},{\"numerator\":[\"1\"],\"denominator\":[\"1\"]}]}"},"operation_detail":"euler_polynomial, shift 0","conclusion_id":"n-c7873b474df0d18a","premise_count":1,"theorem":"Laguerre's theorem on multiplier sequences: if f is a real polynomial whose roots are all real and <= 0, then (f(k))_(k >= 0) is a multiplier sequence, so x^k -> f(k) x^k maps every real-rooted polynomial to a real-rooted polynomial or zero (Laguerre; see T. Craven and G. Csordas, Multiplier sequences for fields, Illinois J. Math. 21 (1977); Polya--Schur, Theorem 40 of P. Branden, arXiv:1410.6601: sum_k f(k) x^k / k! = f(theta) e^x = C e^x x^m prod (1 + x/a_j), a_j > 0); f(k) has one sign for k >= 0, so coefficients of one sign stay of one sign; applied to f(n, .) for each n","lean_route":null,"lean_declarations":["RealRooted.isMultiplierSequence_eval_of_roots_nonpos","RealRooted.isPFMultiplierSequence_eval_of_roots_nonpos","RealRooted.isMultiplierSequence_iff_preserves"],"certificate_hash":"9c7859b42ce7e23e13f2ff60e0e5e967c080975d8630509e2d6c57a0a0327866","verification_polytool":"replayed","verification_lean":"not_attempted","claims":[{"claim":"real_rooted","from_index":0,"region":{"upper":{"closed":true,"value":"0"}}}],"premises":[{"position":0,"node_id":"n-f6268da8d9636534","role":"sequence","name":"Exponential Riordan array (1, x(1+x/2)).","uses":{"claim":"real_rooted","from_index":0,"region":{"upper":{"closed":true,"value":"0"}}},"uses_text":"Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]"}]}],"used_by":[],"used_by_total":0,"links":[],"oeis":[],"bfiles":[],"oeis_texts":[{"oeis_id":"","target":"node","first_row":0,"oeis_offset":0,"reversed":false,"trim_zeros":"none","regular_triangle":false,"rows_shown":10,"polytool_commit":"c48629374597092cc41ef4d6273f37991516f984","triangle_example":"Triangle begins:\n  0: 1;\n  1: 0, 4;\n  2: 0, 4,  9;\n  3: 0, 0, 27,  16;\n  4: 0, 0, 27,  96,   25;\n  5: 0, 0,  0, 240,  250,    36;\n  6: 0, 0,  0, 240, 1125,   540,    49;\n  7: 0, 0,  0,   0, 2625,  3780,  1029,    64;\n  8: 0, 0,  0,   0, 2625, 15120, 10290,  1792,   81;\n  9: 0, 0,  0,   0,    0, 34020, 61740, 24192, 2916, 100;\n","recurrence_sentence":"The row polynomials satisfy (n^4+6*n^3+13*n^2+12*n+4-(4*n^3+18*n^2+14*n-4)*x+4*n^2*x^2)*P(n,x) = -(n^5+5*n^4+7*n^3-n^2-8*n-4-(5*n^4+28*n^3+49*n^2+42*n+20)*x+(8*n^3+34*n^2+58*n+28)*x^2-(4*n^2+8*n+4)*x^3)*P(n-1,x) + ((2*n^4+12*n^3+26*n^2+24*n+8)*x-(8*n^3+44*n^2+68*n+32)*x^2+(8*n^2+16*n+8)*x^3)*d/dx P(n-1,x) for n >= 1, with P(0,x) = 1.","mathematica":"P[0, x_] := 1;\nP[n_, x_] := P[n, x] = Expand[Together[(-(n^5 + 5*n^4 + 7*n^3 - n^2 - 8*n - 4 - (5*n^4 + 28*n^3 + 49*n^2 + 42*n + 20)*x + (8*n^3 + 34*n^2 + 58*n + 28)*x^2 - (4*n^2 + 8*n + 4)*x^3)*P[n - 1, x] + ((2*n^4 + 12*n^3 + 26*n^2 + 24*n + 8)*x - (8*n^3 + 44*n^2 + 68*n + 32)*x^2 + (8*n^2 + 16*n + 8)*x^3)*D[P[n - 1, x], x])/(n^4 + 6*n^3 + 13*n^2 + 12*n + 4 - (4*n^3 + 18*n^2 + 14*n - 4)*x + 4*n^2*x^2)]];\nTable[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten","pari":"P(N) = {my(v = vector(N + 1)); v[1] = 1; for(n = 1, N, my(i = n + 1); v[i] = (-(n^5 + 5*n^4 + 7*n^3 - n^2 - 8*n - 4 - (5*n^4 + 28*n^3 + 49*n^2 + 42*n + 20)*x + (8*n^3 + 34*n^2 + 58*n + 28)*x^2 - (4*n^2 + 8*n + 4)*x^3)*v[i - 1] + ((2*n^4 + 12*n^3 + 26*n^2 + 24*n + 8)*x - (8*n^3 + 44*n^2 + 68*n + 32)*x^2 + (8*n^2 + 16*n + 8)*x^3)*deriv(v[i - 1], x))/(n^4 + 6*n^3 + 13*n^2 + 12*n + 4 - (4*n^3 + 18*n^2 + 14*n - 4)*x + 4*n^2*x^2)); v};\nrow(n, p) = {my(c = Vecrev(p)); c};\nT(N) = {my(v = P(N)); concat(vector(#v, i, row(i - 1, v[i])))};\nT(9)","reading":{"first_row":0,"offset":0,"reversed":false,"trim_zeros":"none","regular_triangle":false}}],"derivation":{"root":"n-97b51734d39ede6c","steps":["reverse","(\u03b8+1)\u00b2"],"edges":["e-01d50252f4aaa594","e-38acf07bf4ec9f74"],"text":"A100861 \u2192 reverse \u2192 (\u03b8+1)\u00b2"},"headline":"A100861 \u2192 reverse \u2192 (\u03b8+1)\u00b2","chain":null}
