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 A316321 #9 Jul 03 2018 02:42:42 %S A316321 0,0,0,0,1,4,16,51,158,463,1330,3742,10438,28877,79619,218997,602079, %T A316321 1655623,4557604,12564084,34697544,96006605,266185703,739530680, %U A316321 2058786037,5742859294,16050179897,44939957405,126052336580,354158412141 %N A316321 Number of "nonlinear" trees on n nodes. %H A316321 J. H. Verner, <a href="https://doi.org/10.1016/S0168-9274(96)00041-4">High-order explicit Runge-Kutta pairs with low stage order</a>, Applied Numerical Mathematics, 22 (1996), 345-347. See Table 2. %F A316321 a(n) = 0 for n <= 4. Thereafter, a(n) = A000081(n) - (n-1) - A000295(n-2) = A000081(n) - 2^(n-2). For example, a(9) = 286 - 8 - 120 = 286 - 2^7 = 158. %Y A316321 Cf. A000081, A000295. %K A316321 nonn %O A316321 1,6 %A A316321 _N. J. A. Sloane_, Jul 02 2018, following a suggestion from Chris Kennedy, Jun 24 2018