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 A286799 Row sums of A286798. 4
 1, 1, 6, 49, 542, 7278, 113824, 2017881, 39842934, 865391422, 20486717908, 524816312106, 14463876594476, 426759508580416, 13423937511765492, 448515527244396873, 15865571912065180326, 592432249691301719190, 23290086526099237126180, 961614574423928988516286, 41607005553456012247259844 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Gheorghe Coserea, Table of n, a(n) for n = 0..200 Luca G. Molinari, Nicola Manini, Enumeration of many-body skeleton diagrams, arXiv:cond-mat/0512342 [cond-mat.str-el], 2006. MATHEMATICA max = 22; y0[x_, t_] = 1; y1[x_, t_] = 0; For[n = 1, n <= max, n++, y1[x_, t_] = 1 + x y0[x, t]^2 + 3 t x^3 y0[x, t]^2 D[y0[x, t], x] + x^2 (2 y0[x, t] D[y0[x, t], x] + t (2 y0[x, t]^3 - D[y0[x, t], x] + y0[x, t] D[y0[x, t], x])) + O[x]^n // Normal // Simplify; y0[x_, t_] = y1[x, t]]; P[n_, t_] := Coefficient[y0[x, t] , x, n]; a[n_] := CoefficientList[P[n, t], t] // Total; Table[a[n], {n, 0, max-1}] (* Jean-François Alcover, May 24 2017, adapted from PARI *) PROG (PARI) A286795_ser(N, t='t) = {   my(x='x+O('x^N), y0=1, y1=0, n=1);   while(n++,     y1 = (1 + x*(1 + 2*t + x*t^2)*y0^2 + t*(1-t)*x^2*y0^3 + 2*x^2*y0*y0');     y1 = y1 / (1+2*x*t); if (y1 == y0, break()); y0 = y1; ); y0; }; A286798_ser(N, t='t) = {   my(v = A286795_ser(N, t)); subst(v, 'x, serreverse(x/(1-x*t*v))); }; Vec(A286798_ser(21, 1)) CROSSREFS Cf. A286798. Sequence in context: A143165 A008786 A274278 * A245797 A046195 A305376 Adjacent sequences:  A286796 A286797 A286798 * A286800 A286801 A286802 KEYWORD nonn AUTHOR Gheorghe Coserea, May 21 2017 STATUS approved

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Last modified April 10 22:35 EDT 2021. Contains 342862 sequences. (Running on oeis4.)