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 A107097 G.f. satisfies: A(A(x)) = A(x)/(1-x), so that the self-COMPOSE transform generates partial sums (A107098). 1
 1, 1, 0, 1, -3, 13, -63, 339, -1982, 12429, -82827, 582589, -4303016, 33240205, -267697961, 2241725581, -19477340744, 175259713769, -1630583565434, 15663877511863, -155168272246709, 1583282220672515, -16623104947488348, 179409709469784087, -1988706708427161585 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,5 LINKS FORMULA G.f. satisfies: A(x) = x + A(x)*Series_Reversion(A(x)). Given g.f. A(x), let G(x) = Series_Reversion(A(x)), then G(x) satisfies: (1) G(x) = 1 - x/A(x), (2) G(x) = x - x*G(G(x)), (3) -G(-x) is the g.f. of A030266, which shifts left under self-COMPOSE. EXAMPLE G.f.: A(x) = x + x^2 + x^4 - 3*x^5 + 13*x^6 - 63*x^7 + 339*x^8 -+... If G(x) = series reversion of g.f. A(x) so that A(G(x)) = x, then G(x) begins: G(x) = x - x^2 + 2*x^3 - 6*x^4 + 23*x^5 - 104*x^6 + 531*x^7 - 2982*x^8 -+... Compare the functional inverse, G(x), to the arithmetic inverse x/A(x): x/A(x) = 1 - x + x^2 - 2*x^3 + 6*x^4 - 23*x^5 + 104*x^6 - 531*x^7 + 2982*x^8 -+... PROG (PARI) {a(n)=local(A, B, F); if(n<1, 0, F=x+2*x^2-3*x^3+x*O(x^n); A=F; for(j=0, n, for(i=0, j, B=serreverse(A); A=(A+subst(B, x, A/(1-x)))/2); A=round(A)); polcoeff(A, n, x))} (PARI) /* A(x) = x + A(x)*Series_Reversion(A(x)): */ {a(n)=local(A=x+x^2); for(i=1, n, A=x+A*serreverse(A+x*O(x^n))); polcoeff(A, n)} CROSSREFS Cf. A107098. Sequence in context: A193112 A192729 A284716 * A202837 A180111 A292183 Adjacent sequences:  A107094 A107095 A107096 * A107098 A107099 A107100 KEYWORD sign AUTHOR Paul D. Hanna, May 12 2005, Jul 23 2011 EXTENSIONS Initial zero removed and offset changed to 1 by Paul D. Hanna, Jul 23 2011 STATUS approved

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Last modified June 27 16:04 EDT 2022. Contains 354896 sequences. (Running on oeis4.)