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 A086611 Row sums of triangle of coefficients (A086610) where T(n,k) is the coefficient of x^n*y^k in f(x,y) that satisfies f(x,y) = (1-x-x^2)/(1-x)^2 + xy*f(x,y)^2. 1
 1, 2, 4, 11, 36, 129, 486, 1892, 7546, 30675, 126642, 529600, 2238782, 9551583, 41075698, 177865921, 774875488, 3393896499, 14936139018, 66014016044, 292892796930, 1304062558529, 5824639004518, 26091657768331 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS FORMULA G.f.: A(x) = (1-x-x^2)/(1-x)^2 + x*A(x)^2. EXAMPLE a(3)=-1+1+6+5=11, a(4)=-2-2+6+20+14=36, a(5)=-3-6-4+30+70+42=129. CROSSREFS Cf. A086610 (triangle), A086632. Sequence in context: A219861 A193058 A179379 * A035098 A328425 A174107 Adjacent sequences:  A086608 A086609 A086610 * A086612 A086613 A086614 KEYWORD nonn AUTHOR Paul D. Hanna, Jul 24 2003 STATUS approved

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Last modified December 3 05:29 EST 2020. Contains 338899 sequences. (Running on oeis4.)