A099136 Inverse integer permutation to A099135.

1, 12, 2, 8, 9, 3, 13, 4, 14, 5, 10, 7, 6, 11, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72

Offset: 1

Author

Reinhard Zumkeller, Sep 29 2004

Keywords

• nonn
• easy

Comments

a(n) <> n iff 1 < n <= 14.

Links

• Index entries for sequences that are permutations of the natural numbers
• Index entries for linear recurrences with constant coefficients, signature (2,-1).

Programs

Mathematica

LinearRecurrence[{2,-1},{1,12,2,8,9,3,13,4,14,5,10,7,6,11,15,16},80] (* Harvey P. Dale, Mar 03 2023 *)

PARI

a(n)=if(n>14,n,[1, 12, 2, 8, 9, 3, 13, 4, 14, 5, 10, 7, 6, 11][n]) \\ Charles R Greathouse IV, Sep 02 2011