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A265342 Permutation of even numbers: a(n) = 2 * A265351(n).

%I A265342 #14 May 25 2017 03:16:59
%S A265342 0,2,4,6,8,22,12,10,16,18,20,58,24,26,76,66,64,70,36,14,40,30,28,34,
%T A265342 48,46,52,54,56,166,60,62,184,174,172,178,72,74,220,78,80,238,228,226,
%U A265342 232,198,68,202,192,190,196,210,208,214,108,38,112,42,44,130,120,118,124,90,32,94,84,82,88,102,100,106,144
%N A265342 Permutation of even numbers: a(n) = 2 * A265351(n).
%C A265342 Iterating this sequence as 1, a(1), a(a(1)), a(a(a(1))), ... yields A264980.
%H A265342 Antti Karttunen, <a href="/A265342/b265342.txt">Table of n, a(n) for n = 0..9841</a>
%F A265342 a(n) = 2 * A265351(n).
%o A265342 (Scheme) (define (A265342 n) (* 2 (A265351 n)))
%o A265342 (Python)
%o A265342 from sympy import factorint
%o A265342 from sympy.ntheory.factor_ import digits
%o A265342 from operator import mul
%o A265342 def a030102(n): return 0 if n==0 else int(''.join(map(str, digits(n, 3)[1:][::-1])), 3)
%o A265342 def a038502(n):
%o A265342     f=factorint(n)
%o A265342     return 1 if n==1 else reduce(mul, [1 if i==3 else i**f[i] for i in f])
%o A265342 def a038500(n): return n/a038502(n)
%o A265342 def a263273(n): return 0 if n==0 else a030102(a038502(n))*a038500(n)
%o A265342 def a263272(n): return a263273(2*n)/2
%o A265342 def a(n): return 2*a263272(a263273(n)) # _Indranil Ghosh_, May 25 2017
%Y A265342 Cf. A265351.
%Y A265342 Cf. also A265341, A263273, A264980.
%K A265342 nonn
%O A265342 0,2
%A A265342 _Antti Karttunen_, Dec 07 2015