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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":"7202355af38c853e54f45762847e00e36ad60344d20c45c38cdcc3c63d3351f6","verification_polytool":"replayed","verification_lean":"not_attempted","claims":[{"claim":"real_rooted","from_index":1,"region":{"upper":{"closed":true,"value":"0"}}},{"claim":"interlacing","from_index":2,"kind":"weak","orientation":"unordered"}],"premises":[{"position":0,"node_id":"n-d55b2cfe05a04774","role":"sequence","name":"Triangle of B-analogs of Stirling numbers of the second kind.","uses":{"claim":"real_rooted","from_index":1,"region":{"upper":{"closed":true,"value":"0"}}},"uses_text":"Every row P_n, n >= 1, 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":1,"oeis_offset":1,"reversed":false,"trim_zeros":"none","regular_triangle":false,"rows_shown":10,"polytool_commit":"c48629374597092cc41ef4d6273f37991516f984","triangle_example":"Triangle begins:\n   1: 1;\n   2: 1,     2;\n   3: 1,     8,      3;\n   4: 1,    26,     27,       4;\n   5: 1,    80,    174,      64,       5;\n   6: 1,   242,    990,     680,     125,       6;\n   7: 1,   728,   5313,    6080,    1975,     216,      7;\n   8: 1,  2186,  27657,   49644,   25375,    4746,    343,     8;\n   9: 1,  6560, 141564,  384384,  290430,   82656,   9996,   512,   9;\n  10: 1, 19682, 717660, 2879440, 3094350, 1257732, 226380, 19104, 729, 10;\n","recurrence_sentence":"The row polynomials satisfy P(n,x) = (1+2*x-x^2)*P(n-2,x) + (2*x-2*x^2)*d/dx P(n-2,x) + 2*x*P(n-1,x) + 2*x*d/dx P(n-1,x) for n >= 3, with P(1,x) = 1, P(2,x) = 1 + 2*x.","mathematica":"P[1, x_] := 1;\nP[2, x_] := 1 + 2*x;\nP[n_, x_] := P[n, x] = Expand[(1 + 2*x - x^2)*P[n - 2, x] + (2*x - 2*x^2)*D[P[n - 2, x], x] + 2*x*P[n - 1, x] + 2*x*D[P[n - 1, x], x]];\nTable[CoefficientList[P[n, x], x], {n, 1, 10}] // Flatten","pari":"P(N) = {my(v = vector(N)); v[1] = 1; v[2] = 1 + 2*x; for(n = 3, N, my(i = n); v[i] = (1 + 2*x - x^2)*v[i - 2] + (2*x - 2*x^2)*deriv(v[i - 2], x) + 2*x*v[i - 1] + 2*x*deriv(v[i - 1], x)); v};\nrow(n, p) = {my(c = Vecrev(p)); c};\nT(N) = {my(v = P(N)); concat(vector(#v, i, row(i, v[i])))};\nT(10)","reading":{"first_row":1,"offset":1,"reversed":false,"trim_zeros":"none","regular_triangle":false}}],"derivation":{"root":"n-d55b2cfe05a04774","steps":["\u03b8+1"],"edges":["e-694ead71eec92686"],"text":"A039755 \u2192 \u03b8+1"},"headline":"A039755 \u2192 \u03b8+1","chain":null}
