A255829 a(n) = n for n < 9; a(9n) = a(n); if every 9th term (a(9), a(18), a(27),...) is deleted, this gives back the original sequence.

1, 2, 3, 4, 5, 6, 7, 8, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 2, 3, 1, 2, 3, 1, 2, 3, 1, 2, 4, 3, 1, 2, 4, 3, 1, 2, 4, 5, 3, 1, 2, 4, 5, 3, 1, 2, 6, 4, 5, 3, 1, 2, 6, 4, 5, 7, 3, 1, 2, 6, 4, 5, 7, 3, 8, 1, 2, 6, 4, 5, 7, 3, 8, 1, 1, 2, 6, 4, 5, 7, 3, 8, 1, 1, 1, 2, 6, 4, 5, 7, 3, 1, 8

Offset: 1

Author

M. F. Hasler, Mar 07 2015

Keywords

• nonn

Comments

A self-generating sequence. This is the m=9 analog of the m=10 variant A126616. Sequence A117943 is the m=3 analog with all terms decreased by 1.

Crossrefs

Cf. A117943, A255824 - A255828, A126616.

Programs

PARI

a(n, m=9)=while(n>=m, if(n%m, n-=n\m, n\=m)); n \\ M. F. Hasler, Mar 07 2015

Formula

a(n) = a(n/9) if n==0 (mod 9); a(n) = a(n - floor(n/9)) otherwise.