Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A074250
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A074250 Smallest p>1 for which n^p ends with n, or -1 if no such p exists. The smallest p for which n is a p-morphic number. +0
1
2, 5, 5, 3, 2, 2, 5, 5, 3, -1, 11, 21, 21, -1, -1, 6, 21, -1, 11, -1, 6, -1, 21, 3, 2, -1, 21, 21, 11, -1, 11, 5, 21, -1, -1, 6, 21, -1, 11, -1, 6, -1, 5, 11, -1, -1, 21, 21, 3, -1, 3, 21, 21, -1, -1, 6, 5, -1, 11, -1, 6, -1, 21, 11, -1, -1, 21, 5, 11, -1, 11, 21, 21, -1, 3, 2, 21, -1, 11, -1, 6, -1, 21, 11, -1, -1, 21, 21, 11, -1, 11, 21, 5, -1 (list; graph; listen)
OFFSET

1,1

COMMENT

For n < 201, 83 numbers cannot be p-morphic numbers, while 116 numbers can be p-morphic number with smallest p varying from e.g. p(5)=3 to p(103)=101. Smallest power p>1 for which n^p has n somewhere (not necessarily at the end!) in its decimal representation is A045537. If positive, the values of p in A045537 are smaller than p in this sequence.

LINKS

Index entries for sequences related to automorphic numbers

EXAMPLE

a(12)=21 because 12^21 is the smallest power (>1) of 12 which ends by 12 (that is 12 is 21-morphic number), a(14)=-1 because there is no power (>1) of 14 which ends by 14 (that is 14 can not be any p-morphic number).

CROSSREFS

Cf. A045537.

Sequence in context: A153354 A153821 A153879 this_sequence A007292 A161013 A115522

Adjacent sequences: A074247 A074248 A074249 this_sequence A074251 A074252 A074253

KEYWORD

sign

AUTHOR

Zak Seidov (zakseidov(AT)yahoo.com), Sep 20 2002

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 10 00:48 EST 2009. Contains 170565 sequences.


AT&T Labs Research