A115309 a(n) = if n<9 then n else 9*a(floor(n/9)) + 8 - n mod 9.

1, 2, 3, 4, 5, 6, 7, 8, 17, 16, 15, 14, 13, 12, 11, 10, 9, 26, 25, 24, 23, 22, 21, 20, 19, 18, 35, 34, 33, 32, 31, 30, 29, 28, 27, 44, 43, 42, 41, 40, 39, 38, 37, 36, 53, 52, 51, 50, 49, 48, 47, 46, 45, 62, 61, 60, 59, 58, 57, 56, 55, 54, 71, 70, 69, 68, 67, 66, 65, 64, 63, 80

Offset

1,2

Comments

Self-inverse permutation of the natural numbers;

A115310(n+7,8) = a(n);

if n is written in base 9 representation, then a(n) is the value after replacing all digits d (but not the leading one) by 8-d.

Links

Table of n, a(n) for n=1..72.

Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A054429, A115303, A115304, A115305, A115306, A115307, A115308, A106649.

Sequence in context: A269356 A269358 A356331 * A171722 A146029 A140576

Adjacent sequences: A115306 A115307 A115308 * A115310 A115311 A115312

Keyword

nonn,base

Author

Reinhard Zumkeller, Jan 20 2006

Status

approved