%I #10 Jan 02 2021 11:24:18
%S 1,1,2,6,20,72,272,1063,4262,17432,72448,305074,1298812,5581188,
%T 24175560,105448157,462745106,2041634108,9050879192,40296196096,
%U 180099939464,807757872276,3634378951656,16399912908504,74201196229816
%N Revert transform of (1 - x - 2x^2 + x^3)/(1 - 2x^2).
%H <a href="/index/Res#revert">Index entries for reversions of series</a>
%F Recurrence: 49*(n-2)*(n-1)*n*(324*n^4 - 4896*n^3 + 27331*n^2 - 66829*n + 60376)*a(n) = 14*(n-2)*(n-1)*(6480*n^5 - 107640*n^4 + 693860*n^3 - 2158612*n^2 + 3214669*n - 1809319)*a(n-1) - 4*(n-2)*(14256*n^6 - 272448*n^5 + 2120024*n^4 - 8564544*n^3 + 18871769*n^2 - 21420614*n + 9740185)*a(n-2) - 16*(3240*n^7 - 73260*n^6 + 705778*n^5 - 3754269*n^4 + 11895329*n^3 - 22403869*n^2 + 23150751*n - 10079360)*a(n-3) - 16*(n-4)*(n-2)*(2592*n^5 - 46944*n^4 + 325028*n^3 - 1067288*n^2 + 1640321*n - 921819)*a(n-4) + 128*(n-5)*(n-4)*(2*n - 11)*(324*n^4 - 3600*n^3 + 14587*n^2 - 25559*n + 16306)*a(n-5). - _Vaclav Kotesovec_, Jan 02 2021
%t Rest[CoefficientList[InverseSeries[Series[x*(1 - x - 2x^2 + x^3)/(1 - 2x^2), {x, 0, 40}], x], x]] (* _Vaclav Kotesovec_, Jan 02 2021 *)
%K nonn
%O 1,3
%A _Olivier GĂ©rard_