This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A055364 #19 Mar 16 2022 05:54:53
%S A055364 1,4,10,22,42,73,119,184,272,389,540,731,969,1261,1614,2037,2538,3126,
%T A055364 3811,4603,5512,6550,7728,9058,10553,12226,14090,16160,18450,20975,
%U A055364 23751,26794,30120,33747,37692,41973,46609,51619,57022,62839,69090,75796,82979
%N A055364 Number of asymmetric mobiles (circular rooted trees) with n nodes and 3 leaves.
%H A055364 Georg Fischer, <a href="/A055364/b055364.txt">Table of n, a(n) for n = 5..129</a>
%H A055364 <a href="/index/Mo#mobiles">Index entries for sequences related to mobiles</a>
%H A055364 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (3,-2,-1,0,1,2,-3,1).
%F A055364 G.f.: x^5*(x^3+x+1)/((1-x^2)*(1-x^3)*(1-x)^3).
%F A055364 a(n) = A055278(4 - n) for all n in Z. - _Michael Somos_, Jun 29 2015
%e A055364 G.f. = x^5 + 4*x^6 + 10*x^7 + 22*x^8 + 42*x^9 + 73*x^10 + 119*x^11 + ...
%t A055364 a[ n_] := Quotient[ 3 n^4 - 28 n^3 + 102 n^2 - 180 n + 144, 144];
%o A055364 (PARI) {a(n) = (3*n^4 - 28*n^3 + 102*n^2 - 180*n + 144) \ 144}; /* _Michael Somos_, Jun 29 2015 */
%o A055364 (PARI) {a(n) = if( n<1, n = -n; polcoeff( (1 + x^2 + x^3) / ((1 - x)^3 * (1 - x^2) * (1 - x^3)) + x * O(x^n), n), polcoeff( x^5 * (1 + x + x^3) / ((1 - x)^3 * (1 - x^2) * (1 - x^3)) + x * O(x^n), n))}; /* _Michael Somos_, Jun 29 2015 */
%Y A055364 Column 3 of A055363.
%Y A055364 Cf. A055278.
%K A055364 nonn
%O A055364 5,2
%A A055364 _Christian G. Bower_, May 16 2000