Revision History for A117817
(Underlined text is an addition;
strikethrough text is a deletion.)
Showing all changes.
|
| |
|
| A117817
|
|
Let T_n be the infinite sequence formed by starting with 1 and repeatedly reversing the digits and adding n to get the next term. If T_n eventually reaches a cycle, sequence gives length of that cycle, otherwise -1.
(history;
published version)
|
| |
|
|
#8 by N. J. A. Sloane at Mon May 26 23:48:47 EDT 2014
|
|
| LINKS
|
N. J. A. Sloane and others, <a href="/A117831wiki/a117831.txtSequences_of_RADD_type">Sequences of RADD type</a>>, OEIS wiki.
|
| |
|
|
Discussion
|
| Mon May 26
| 23:48
| OEIS Server: https://oeis.org/edit/global/2223
|
| |
| |
|
|
#7 by N. J. A. Sloane at Thu Apr 03 11:35:06 EDT 2014
|
|
| COMMENTS
|
a(multiple of 10) = -1 (see A117816). a(15) = -1 (see A118532). a(n) is a multiple of 9/gcd(9,n) unless it is -1. - . - _Martin Fuller (martin_n_fuller(AT)btinternet.com), _, May 12 2006
|
|
| EXTENSIONS
|
a(33) onwards from T. D. Noe and _Martin Fuller (martin_n_fuller(AT)btinternet.com), _, May 10 2006
|
| |
|
|
Discussion
|
| Thu Apr 03
| 11:35
| OEIS Server: https://oeis.org/edit/global/2137
|
| |
| |
|
|
#6 by Russ Cox at Fri Mar 30 17:22:42 EDT 2012
|
|
| EXTENSIONS
|
a(33) onwards from _T. D. Noe (noe(AT)sspectra.com) _ and Martin Fuller (martin_n_fuller(AT)btinternet.com), May 10 2006
|
| |
|
|
Discussion
|
| Fri Mar 30
| 17:22
| OEIS Server: https://oeis.org/edit/global/120
|
| |
| |
|
|
#5 by Russ Cox at Fri Mar 30 16:50:25 EDT 2012
|
|
| AUTHOR
|
_N. J. A. Sloane (njas(AT)research.att.com), _, following discussions with Luc Stevens, May 04 2006
|
| |
|
|
Discussion
|
| Fri Mar 30
| 16:50
| OEIS Server: https://oeis.org/edit/global/110
|
| |
| |
|
|
#4 by N. J. A. Sloane at Thu Nov 11 07:34:06 EST 2010
|
|
| LINKS
|
N. J. A. Sloane, <a href="="/A117831/a117831.txt">Sequences of RADD type</a>
|
|
| KEYWORD
|
sign,base,new
|
| |
| |
|
|
#3 by N. J. A. Sloane at Fri Feb 27 03:00:00 EST 2009
|
|
| LINKS
|
N. J. A. Sloane, <a href="http://www.research.att.com/~njas/sequences/a117831.txt">Sequences of RADD type</a>
|
|
| KEYWORD
|
sign,base,new
|
|
| AUTHOR
|
N. J. A. Sloane (njas, (AT)research.att.com), following discussions with Luc Stevens, May 04 2006
|
| |
| |
|
|
#2 by N. J. A. Sloane at Fri Sep 29 03:00:00 EDT 2006
|
|
| DATA
|
9, 81, 3, 54, 207, 30, 63, 27, 1, -1, 9, 15, 18, 72, -1, 90, 54, 13, 18, -1, 15, 9, 9, 36, 45, 18, 9, 36, 18, -1, 9, 9, 3, 36, 72, 2, 27, 18, 3, -1, 18, 57, 63, 9, 22, 90, 18, 30, 54, -1, 6, 99, 54, 13, 36, 207, 12, 63, 45, -1, 36, 27, 30, 108, 36, 264, 99, 36, 3, -1, 18, 22, 45, 90, 12, 45, 117, 192, 18, -1, 36, 45, 63, 168, 1008, 36, 24, 306, 9, -1, 99, 639, 36, 54, 144, 18, 225, 468, 1, -1, 18, 300, 189, 171, 765, 90, 45, 462, 90, -1, 9, 513, 63, 69
|
|
| COMMENTS
|
Fora(multiple of 10) = -1 (see A117816). a(15) = -1 (see A118532). a(n) is a discussionmultiple of 9/gcd(9,n) unless it theis -1. - Martin entriesFuller (martin_n_fuller(AT)btinternet.com), May see12 A117817.2006
For a discussion of the -1 entries see A117816.
|
|
| KEYWORD
|
nonnsign,base,new
|
| |
| |
|
|
#1 by N. J. A. Sloane at Fri May 19 03:00:00 EDT 2006
|
|
| NAME
|
Let T_n be the infinite sequence formed by starting with 1 and repeatedly reversing the digits and adding n to get the next term. If T_n eventually reaches a cycle, sequence gives length of that cycle, otherwise -1.
|
|
| DATA
|
9, 81, 3, 54, 207, 30, 63, 27, 1, -1, 9, 15, 18, 72, -1, 90, 54, 13, 18, -1, 15, 9, 9, 36, 45, 18, 9, 36, 18, -1, 9, 9, 3, 36, 72, 2, 27, 18, 3, -1, 18, 57, 63, 9, 22, 90, 18, 30, 54, -1, 6, 99, 54, 13, 36, 207, 12, 63, 45, -1, 36, 27, 30, 108, 36, 264, 99, 36, 3, -1, 18, 22, 45, 90, 12, 45, 117, 192, 18, -1, 36, 45, 63, 168, 1008, 36, 24
|
|
| OFFSET
|
1,1
|
|
| COMMENTS
|
For a discussion of the -1 entries see A117817.
|
|
| LINKS
|
N. J. A. Sloane, <a href="http://www.research.att.com/~njas/sequences/a117831.txt">Sequences of RADD type</a>
|
|
| MATHEMATICA
|
ReverseNum[n_] := FromDigits[Reverse[IntegerDigits[n]]]; maxLen=10000; Table[z=1; lst={1}; While[z=ReverseNum[z]+n; !MemberQ[lst, z] && Length[lst]<maxLen, AppendTo[lst, z]]; If[Length[lst]<maxLen, Length[lst]-Position[lst, z][[1, 1]]+1, -1], {n, 100}] (Noe)
|
|
| CROSSREFS
|
See A117817 for the -1 entries and cross-references to T_1 through T_16.
|
|
| KEYWORD
|
nonn,base,new
|
|
| AUTHOR
|
njas, following discussions with Luc Stevens, May 04 2006
|
|
| EXTENSIONS
|
a(21)-a(33) from Luc Stevens, May 08 2006
a(33) onwards from T. D. Noe (noe(AT)sspectra.com) and Martin Fuller (martin_n_fuller(AT)btinternet.com), May 10 2006
|
|
| STATUS
|
approved
|
| |
| |
|
|
