A180199 a(n) = A180201(A180201(n)).

0, 1, 2, 3, 4, 5, 6, 7, 9, 8, 11, 10, 12, 13, 14, 15, 19, 18, 17, 16, 22, 23, 20, 21, 25, 24, 27, 26, 28, 29, 30, 31, 39, 38, 37, 36, 34, 35, 32, 33, 45, 44, 47, 46, 40, 41, 42, 43, 51, 50, 49, 48, 54, 55, 52, 53, 57, 56, 59, 58, 60, 61, 62, 63, 79, 78, 77, 76, 74, 75, 72, 73, 69

Offset: 0

Author

Reinhard Zumkeller, Aug 15 2010

Keywords

• nonn

Comments

Permutation of the natural numbers with inverse A180198;

a(A180200(n)) = A180200(a(n)) = A180201(n);

a(A075427(n)) = A075427(n).

Links

• Index entries for sequences that are permutations of the natural numbers

Programs

R

nmax <- 31 # by choice
a <- 1:3
for(n in 1:nmax) for(k in 0:3){
if(n %% 2 == 0) a[4*n + k] <- 2*a[2*n + (k == 2 | k == 3)] + (k == 0 | k == 2)
else            a[4*n + k] <- 2*a[2*n + (k == 2 | k == 3)] + (k == 1 | k == 3)
}
(a <- c(0,a))
# Yosu Yurramendi, Oct 25 2020