|
Search: id:A069881
|
|
|
| A069881 |
|
Numbers n such that n and 2n+1 are both palindromes. |
|
+0
1
|
|
| 1, 2, 3, 4, 5, 55, 151, 161, 171, 181, 191, 252, 262, 272, 282, 292, 353, 363, 373, 383, 393, 454, 464, 474, 484, 494, 555, 5555, 15051, 15151, 15251, 15351, 15451, 16061, 16161, 16261, 16361, 16461, 17071, 17171, 17271, 17371, 17471, 18081, 18181
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
COMMENT
|
Note that any number with all digits = 5 (A002279) is part of this sequence. - Jim McCann (jmccann(AT)umich.edu), Jul 16 2002
|
|
EXAMPLE
|
151 is a member as 2*151 + 1 = 303 is also a palindrome.
|
|
PROGRAM
|
(Perl) $a = 1; while((@b = split("|", $a) and @c = split("|", 2*$a+1) and (join("", reverse(@b)) eq join("", @b) and join("", reverse(@c)) eq join("", @c) and eval("print \"\$a \"; return 0; "))) or ++$a) { }
|
|
CROSSREFS
|
Sequence in context: A024638 A037330 A062939 this_sequence A004856 A037327 A075832
Adjacent sequences: A069878 A069879 A069880 this_sequence A069882 A069883 A069884
|
|
KEYWORD
|
nonn,base
|
|
AUTHOR
|
Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Apr 30 2002
|
|
EXTENSIONS
|
More terms from Jim McCann (jmccann(AT)umich.edu), Jul 16 2002
|
|
|
Search completed in 0.002 seconds
|
