%I
%S 1,2,3,4,5,6,7,8,10,11,12,13,14,16,17,19,20,22,24,26,28,29,31,32,34,
%T 37,38,40,41,43,44,48,52,53,56,58,59,62,64,67,68,71,74,76,79,80,82,86,
%U 88,89,96,101,104,106,107,109,112,116,118,124,127,128,131,134
%N Sequence A209636 (or A209637) sorted into ascending order.
%C These are Matulanumbers (see A061773) for the rooted trees where no vertices with more than one nonleaf branch ever occur. In other words, natural numbers which are either some power of 2, or of the form 2^k * p_i, where k >= 0, and p_i is the ith prime (A000040(i)), with i being one of the terms of this sequence.
%H <a href="/index/Mat#matula">Index entries for sequences related to MatulaGoebel numbers</a>
%o (Python)
%o from sympy import prime
%o def a(n):
%o n = 2*n
%o m = 1
%o if n<2: return 1
%o while n>1:
%o if n%2==0:
%o n//=2
%o m*=2
%o else:
%o n=(n  1)//2
%o m=prime(m)
%o return m
%o print(sorted([a(n) for n in range(101)])) # _Indranil Ghosh_, May 26 2017
%Y Sorted version of A209636 and A209637.
%Y Subset of A093641 and A122132.
%K nonn
%O 0,2
%A _Antti Karttunen_, Mar 11 2012
