cp's OEIS Frontend

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.

A227298 The number of squares added in the n-th step of a Pythagoras tree of the 30-60-90 triangle, using the rule larger squares come first.

This page as a plain text file.
%I A227298 #11 Jul 10 2013 03:33:29
%S A227298 1,2,4,8,16,30,56,102,186,340,624,1148
%N A227298 The number of squares added in the n-th step of a Pythagoras tree of the 30-60-90 triangle, using the rule larger squares come first.
%C A227298 Growth of the Pythagoras tree based on the triangle with internal angles of 30, 60 and 90 degrees.
%C A227298 The generating rule is expansion in sequential order on each stage; the larger squares (opposite to the 60 deg angle) come first. The generating order labeled by "stage-number" starts as 1-1; 2-1, 2-2; 3-1, 3-2, 3-3, 3-4;...and so on. Overlap is prohibited, i.e., if any part of a new element in the next generating order cuts into any previous (existing, lower order) one, that new elements will be not be inserted/added: lower generating orders have precedence over higher generating orders.
%C A227298 The non-overlap rule limits the growth of the sequence to a(n+1) <= 2*a(n).
%C A227298 For Pythagoras tree based on isosceles right triangle with the same rule, the sequence will be A053599(n-1) + 1.
%H A227298 Kival Ngaokrajang, <a href="/A227298/a227298.jpg">Illustration for n = 1..11</a>
%Y A227298 Cf. A053599, A226454.
%K A227298 nonn,more
%O A227298 1,2
%A A227298 _Kival Ngaokrajang_, Jul 05 2013