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 A382060 #28 Mar 20 2025 06:01:29 %S A382060 1,1,1,1,2,4,10,27,77,231,719,2302,7541,25177,85405,293635,1021272, %T A382060 3587674,12713796,45402113,163244197,590529759,2147915920,7851127319, %U A382060 28826079193,106268313333,393218951710,1459969448090,5437679646441,20311366912839,76072367645347,285623120079865,1074888308119285 %N A382060 Number of rooted ordered trees with n nodes such that the degree of each node is less than or equal to its depth plus one. %C A382060 The root vertex is depth d=0 and is to have <= d+1 = 1 children so these are "planted" trees. %H A382060 John Tyler Rascoe, <a href="/A382060/a382060_3.py.txt">Python program</a>. %H A382060 Kevin Ryde, <a href="/A382060/a382060.gp.txt">PARI/GP program</a> %e A382060 a(5) = 4 counts: %e A382060 depth: %e A382060 o o o o 0 %e A382060 | | | | %e A382060 o o o o 1 %e A382060 | | / \ / \ %e A382060 o o o o o o 2 %e A382060 | / \ | | %e A382060 o o o o o 3 %e A382060 | %e A382060 o 4 %o A382060 (Python) # see links %o A382060 (PARI) \\ see links %Y A382060 Cf. A000081, A000108, A000957, A036765, A288942, A358586, A358590, A380761. %K A382060 nonn %O A382060 0,5 %A A382060 _John Tyler Rascoe_, Mar 14 2025