# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a055349 Showing 1-1 of 1 %I A055349 #18 Mar 19 2022 16:40:48 %S A055349 1,2,0,6,3,0,24,36,8,0,120,360,220,30,0,720,3600,4200,1500,144,0,5040, %T A055349 37800,71400,47250,11508,840,0,40320,423360,1176000,1234800,545664, %U A055349 98784,5760,0,362880,5080320,19474560,29635200,20469456,6618528,940896,45360,0 %N A055349 Triangle of labeled mobiles (circular rooted trees) with n nodes and k leaves. %H A055349 Andrew Howroyd, Table of n, a(n) for n = 1..1275 (first 50 rows) %H A055349 Index entries for sequences related to mobiles %F A055349 E.g.f. satisfies A(x, y) = x*y - x*log(1-A(x, y)). [Corrected by _Sean A. Irvine_, Mar 19 2022] %e A055349 Triangle begins: %e A055349 1; %e A055349 2, 0; %e A055349 6, 3, 0; %e A055349 24, 36, 8, 0; %e A055349 120, 360, 220, 30, 0; %e A055349 720, 3600, 4200, 1500, 144, 0; %e A055349 5040, 37800, 71400, 47250, 11508, 840, 0; %e A055349 ... %t A055349 T[rows_] := {{1}}~Join~((cc = CoefficientList[#, y]; Append[Rest[cc], 0] * Length[cc]!)& /@ (CoefficientList[InverseSeries[x/(y-Log[1-x + O[x]^rows] ), x], x][[3;;]])); %t A055349 T[9] // Flatten (* _Jean-François Alcover_, Oct 31 2019 *) %o A055349 (PARI) %o A055349 A(n)={my(v=Vec(serlaplace(serreverse(x/(y - log(1-x + O(x^n))))))); vector(#v, i, Vecrev(v[i]/y, i))} %o A055349 { my(T=A(10)); for(i=1, #T, print(T[i])) } \\ _Andrew Howroyd_, Sep 23 2018 %Y A055349 Row sums give A038037. %Y A055349 Columns 1..8 are A000142, A055303, A055350, A055351, A055352, A055353, A055354, A055355. %Y A055349 Cf. A055340, A055356, A055363. %K A055349 nonn,tabl,eigen %O A055349 1,2 %A A055349 _Christian G. Bower_, May 15 2000 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE