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

0, 2, 4, 6, 8, 22, 12, 10, 16, 18, 20, 58, 24, 26, 76, 66, 64, 70, 36, 14, 40, 30, 28, 34, 48, 46, 52, 54, 56, 166, 60, 62, 184, 174, 172, 178, 72, 74, 220, 78, 80, 238, 228, 226, 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

Offset: 0

Author

Antti Karttunen, Dec 07 2015

Keywords

• nonn

Comments

Iterating this sequence as 1, a(1), a(a(1)), a(a(a(1))), ... yields A264980.

Links

• Antti Karttunen, Table of n, a(n) for n = 0..9841

Crossrefs

Cf. A265351.

Cf. also A265341, A263273, A264980.

Programs

Python

from sympy import factorint
from sympy.ntheory.factor_ import digits
from operator import mul
def a030102(n): return 0 if n==0 else int(''.join(map(str, digits(n, 3)[1:][::-1])), 3)
def a038502(n):
    f=factorint(n)
    return 1 if n==1 else reduce(mul, [1 if i==3 else i**f[i] for i in f])
def a038500(n): return n/a038502(n)
def a263273(n): return 0 if n==0 else a030102(a038502(n))*a038500(n)
def a263272(n): return a263273(2*n)/2
def a(n): return 2*a263272(a263273(n)) # Indranil Ghosh, May 25 2017

Scheme

(define (A265342 n) (* 2 (A265351 n)))

Formula

a(n) = 2 * A265351(n).