A140264 Inverse permutation to A140263.

0, 1, 2, 5, 7, 3, 6, 4, 8, 17, 19, 15, 23, 25, 21, 11, 13, 9, 18, 16, 20, 12, 10, 14, 24, 22, 26, 53, 55, 51, 59, 61, 57, 47, 49, 45, 71, 73, 69, 77, 79, 75, 65, 67, 63, 35, 37, 33, 41, 43, 39, 29, 31, 27, 54, 52, 56, 48, 46, 50, 60, 58, 62, 36, 34, 38, 30, 28, 32, 42, 40, 44

Offset

0,3

Links

Table of n, a(n) for n=0..71.

Index entries for sequences that are permutations of the natural numbers

Formula

a(n) = A140266(n+1)-1.

Prog

(Scheme) (define (A140264 n) (- (A140266 (+ 1 n)) 1))
(Python)
def a117966(n):
    if n==0: return 0
    if n%3==0: return 3*a117966(n/3)
    elif n%3==1: return 3*a117966((n - 1)/3) + 1
    else: return 3*a117966((n - 2)/3) - 1
def Z(z): return 2*z if z>0 else 2*abs(z) + 1
def a140266(n): return Z(a117966(n - 1))
def a(n): return a140266(n + 1) - 1 # Indranil Ghosh, Jun 07 2017

Crossrefs

Inverse: A140263.

Sequence in context: A097964 A133133 A024710 * A140263 A073929 A361329

Adjacent sequences: A140261 A140262 A140263 * A140265 A140266 A140267

Keyword

nonn

Author

Antti Karttunen, May 19 2008

Status

approved