OFFSET
0,2
COMMENTS
Sequence A209638 gives the same terms sorted into ascending order.
REFERENCES
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.
PROG
(Python)
from sympy import prime
from mpmath import log
def a054429(n): return 3*(2**int(log(n, 2))) - (n + 1)
def a209636(n):
n = 2*n
m = 1
if n<2: return 1
while n>1:
if n%2==0:
n/=2
m*=2
else:
n=(n - 1)/2
m=prime(m)
return m
def a(n): return 1 if n==0 else a209636(a054429(n)) # Indranil Ghosh, May 26 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Antti Karttunen, Mar 11 2012
STATUS
approved