Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A123175
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A123175 Table (read by antidiagonals) where t(0,0)=1, t(m,n) = number of terms above and to the left of t(m,n) (i.e. number of t(k,j)'s, where 0<=k<=m, 0<=j<=n, excluding the t(m,n) case itself) which are coprime to (m+n). +0
1
1, 1, 1, 2, 3, 2, 3, 4, 4, 3, 3, 5, 4, 5, 3, 5, 8, 10, 10, 8, 5, 3, 5, 4, 5, 4, 5, 3, 7, 13, 17, 19, 19, 17, 13, 7, 7, 12, 12, 14, 13, 14, 12, 12, 7, 6, 12, 17, 21, 24, 24, 21, 17, 12, 6, 7, 10, 12, 14, 15, 13, 15, 14, 12, 10, 7, 11, 21, 29, 35, 39, 41, 41, 39, 35, 29, 21, 11, 7, 11, 13 (list; table; graph; listen)
OFFSET

0,4

EXAMPLE

The first 4 columns and first 6 rows (excluding t(5,3)) of the table is:

1,1,2,3

1,3,4,5

2,4,4,10

3,5,10,5

3,8,4,19

5,5,17,

The number of these terms which are coprime to (5+3) is 14 (the odd terms). So t(5, 3) = 14.

MATHEMATICA

t[0, 0] = 1; t[m_, n_] := t[m, n] = Block[{c = 0}, Do[ Do[ If[k == m && j == n, Continue[]]; If[GCD[t[k, j], m + n] == 1, c++ ]; , {j, 0, n}]; , {k, 0, m}]; c]; Flatten[Table[t[d - i, i], {d, 0, 12}, {i, 0, d}]] (*Chandler*)

CROSSREFS

Adjacent sequences: A123172 A123173 A123174 this_sequence A123176 A123177 A123178

Sequence in context: A124524 A124525 A106788 this_sequence A143998 A054237 A129600

KEYWORD

nonn,tabl

AUTHOR

Leroy Quet (qq-quet(AT)mindspring.com), Nov 04 2006

EXTENSIONS

Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 11 2006

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 October 7 14:39 EDT 2008. Contains 144666 sequences.


AT&T Labs Research