A132340 a(n+1) = if {a(k):1<=k<=n} is a permutation of [1:n] then 2*a(n) else a(n)-1.

1, 2, 4, 3, 6, 5, 10, 9, 8, 7, 14, 13, 12, 11, 22, 21, 20, 19, 18, 17, 16, 15, 30, 29, 28, 27, 26, 25, 24, 23, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 94, 93, 92, 91, 90, 89, 88, 87, 86, 85

Offset: 1

Author

Reinhard Zumkeller, Aug 20 2007

Keywords

• nonn

Comments

Self-inverse permutation of natural numbers;

a(A052955(n)) = A027383(n);

a(A052955(n)-1)=a(A052955(n))/2; a(A052955(n)+1)=a(A052955(n))-1.

Almost certainly A132666 is a duplicate of this entry. - R. J. Mathar, Jun 12 2008

Links

• R. Zumkeller, Table of n, a(n) for n = 1..10000
• Index entries for sequences that are permutations of the natural numbers