The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A228722 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
Showing all changes.

A228722

Largest number <= n with alternating parities of digits in decimal representation.
(history; published version)

#5 by Reinhard Zumkeller at Sat Aug 31 17:13:19 EDT 2013

STATUS

editing

approved

#4 by Reinhard Zumkeller at Sat Aug 31 16:54:37 EDT 2013

COMMENTS

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

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

EXAMPLE

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

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

PROG

(Haskell)

a228722 n = head [x | x <- [n, n-1 ..], a228710 x == 1]

#3 by Reinhard Zumkeller at Sat Aug 31 16:53:33 EDT 2013

NAME

allocated for Reinhard ZumkellerLargest number <= n with alternating parities of digits in decimal representation.

DATA

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

OFFSET

0,3

LINKS

Reinhard Zumkeller, <a href="/A228722/b228722.txt">Table of n, a(n) for n = 0..10000</a>

KEYWORD

allocated

nonn,base

AUTHOR

Reinhard Zumkeller, Aug 31 2013

STATUS

approved

editing

#2 by Reinhard Zumkeller at Sat Aug 31 07:06:59 EDT 2013

KEYWORD

allocating

allocated

#1 by Reinhard Zumkeller at Sat Aug 31 07:06:59 EDT 2013

NAME

allocated for Reinhard Zumkeller

KEYWORD

allocating

STATUS

approved