A264983 - OEIS

A264983

Odd bisection of A263273.

1, 3, 7, 5, 9, 19, 13, 21, 25, 11, 15, 23, 17, 27, 55, 37, 57, 73, 31, 39, 67, 49, 63, 61, 43, 75, 79, 29, 33, 65, 47, 45, 59, 41, 69, 77, 35, 51, 71, 53, 81, 163, 109, 165, 217, 91, 111, 199, 145, 171, 181, 127, 219, 235, 85, 93, 193, 139, 117, 175, 121, 201, 229, 103, 147, 211

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,2

LINKS

Indranil Ghosh, Table of n, a(n) for n = 0..10000

FORMULA

a(n) = A263273(2n + 1).

MATHEMATICA

f[n_] := Block[{g, h}, g[x_] := x/3^IntegerExponent[x, 3]; h[x_] := x/g@ x; If[n == 0, 0, FromDigits[Reverse@ IntegerDigits[#, 3], 3] &@ g[n] h[n]]]; t = Select[f /@ Range@ 130, OddQ] (* Michael De Vlieger, Jan 04 2016, after Jean-François Alcover at A263273 *)

PROG

(Scheme) (define (A264983 n) (A263273 (+ 1 n n)))

(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)