Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A067870
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A067870 Numbers n such that n and 3^n end with the same digit. +0
1
7, 13, 27, 33, 47, 53, 67, 73, 87, 93, 107, 113, 127, 133, 147, 153, 167, 173, 187, 193, 207, 213, 227, 233, 247, 253, 267, 273, 287, 293, 307, 313, 327, 333, 347, 353, 367, 373, 387, 393, 407, 413, 427, 433, 447, 453, 467, 473, 487, 493, 507, 513, 527, 533 (list; graph; listen)
OFFSET

1,1

COMMENT

3^13=1594323 hence 13 is in the sequence

Except for the first term, a(n)=20*n-a(n-1), (with a(1)=13) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Oct 23 2009]

FORMULA

a(2n+1)=20n-13 a(2n)=20n-7

a(n)=20*n-a(n-1), (with a(1)=13) [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Oct 23 2009]

EXAMPLE

for n=2, a(2)=20*2-13=27; n=3, a(3)=20*3-27=33; n=4, a(4)=20*4-33=47 [From Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Oct 23 2009]

CROSSREFS

Sequence in context: A111721 A060455 A072579 this_sequence A147258 A146718 A146646

Adjacent sequences: A067867 A067868 A067869 this_sequence A067871 A067872 A067873

KEYWORD

easy,nonn,base

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), Mar 07 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 November 27 14:50 EST 2009. Contains 167570 sequences.


AT&T Labs Research