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%I #10 May 26 2017 08:55:08
%S 1,2,3,4,5,7,6,8,11,17,13,19,10,14,12,16,31,59,41,67,29,43,37,53,22,
%T 34,26,38,20,28,24,32,127,277,179,331,109,191,157,241,79,139,101,163,
%U 71,107,89,131,62,118,82,134,58,86,74,106,44,68,52,76,40,56,48
%N Matula-numbers computed for rooted trees encoded by A071162 when interpreted in once-halved bit-tuple format.
%C Sequence A209638 gives the same terms sorted into ascending order.
%D Mueller, Szymanski, Knop and Trinajstic, A Comparison between the Matula Numbers and Bit-tuple Notation for Rooted Trees J. Chem. Inf. Comput. Sci. 1995, 35, pp. 211--213.
%F a(n) = A209636(A054429(n)) = A127301(A057505(A071163(n))) = A127301(A057163(A071163(n))).
%o (Python)
%o from sympy import prime
%o from mpmath import log
%o def a054429(n): return 3*(2**int(log(n, 2))) - (n + 1)
%o def a209636(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 def a(n): return 1 if n==0 else a209636(a054429(n)) # _Indranil Ghosh_, May 26 2017
%K nonn,easy
%O 0,2
%A _Antti Karttunen_, Mar 11 2012
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