A228722 - OEIS

A228722

Largest number <= n with alternating parities of digits in decimal representation.

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 12, 12, 14, 14, 16, 16, 18, 18, 18, 21, 21, 23, 23, 25, 25, 27, 27, 29, 30, 30, 32, 32, 34, 34, 36, 36, 38, 38, 38, 41, 41, 43, 43, 45, 45, 47, 47, 49, 50, 50, 52, 52, 54, 54, 56, 56, 58, 58, 58, 61, 61, 63, 63, 65, 65

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

COMMENTS

a(n) <= n <= A228723(n) and A228710(a(n)) = 1;

a(A030141(n)) = A030141(n); a(A228709(n)) < A228709(n).

LINKS

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

EXAMPLE

a(100) = 98; a(1000) = 989; a(10000) = 9898; a(100000) = 98989;

a(101) = 101; a(1001) = 989.

PROG