A259043 a(n) = if n < 10 then n else a(floor(n/10) + n mod 10) + n mod 10.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 3, 5, 7, 9, 11, 13, 15, 17, 10, 2, 4, 6, 8, 10, 12, 14, 16, 9, 12, 3, 5, 7, 9, 11, 13, 15, 8, 11, 14, 4, 6, 8, 10, 12, 14, 7, 10, 13, 16, 5, 7, 9, 11, 13, 6, 9, 12, 15, 18, 6, 8, 10, 12, 5, 8, 11, 14, 17, 20, 7, 9, 11, 4, 7

Offset: 0

Author

Reinhard Zumkeller, Jun 17 2015

Keywords

• nonn
• base

Comments

a(A259046(n)) = n and a(m) != n for m < A259046(n).

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A076314, A007953, A008687, A259046.

Programs

Haskell

a259043 x = if x < 10 then x else a259043 (x' + d) + d
            where (x', d) = divMod x 10

PARI

a(n) = if (n<10, n, my(u=n%10); a(n\10 + u) + u); \\ Michel Marcus, Jan 23 2022