login
This site is supported by donations to The OEIS Foundation.

 

Logo

Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing.
Other ways to donate

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A162922 Square array read by antidiagonals: m is the a(n,m)th positive integer among those which are coprime to n. Or a(n,m) = 0 if m and n are not coprime. 1
1, 1, 2, 1, 0, 3, 1, 2, 2, 4, 1, 0, 0, 0, 5, 1, 2, 2, 3, 3, 6, 1, 0, 3, 0, 4, 0, 7, 1, 2, 0, 4, 3, 0, 4, 8, 1, 0, 3, 0, 0, 0, 5, 0, 9, 1, 2, 2, 4, 2, 5, 4, 6, 5, 10, 1, 0, 0, 0, 5, 0, 6, 0, 0, 0, 11, 1, 2, 2, 3, 3, 6, 3, 7, 5, 7, 6, 12, 1, 0, 3, 0, 4, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

EXAMPLE

Rows 1 through 7 of the array:

n=1: 1,2,3,4,5,6,7,8,9,...

n=2: 1,0,2,0,3,0,4,0,5,...

n=3: 1,2,0,3,4,0,5,6,0,...

n=4: 1,0,2,0,3,0,4,0,5,...

n=5: 1,2,3,4,0,5,6,7,8,...

n=6: 1,0,0,0,2,0,3,0,0,...

n=7: 1,2,3,4,5,6,0,7,8,...

MAPLE

N:= 20: # for the first N antidiagonals

for n from 1 to N do

  t:= 0:

  for m from 1 to N+1-n do

    if igcd(m, n)=1 then

      t:= t+1; T[n, m]:= t;

    else T[n, m]:= 0

    fi

  od

od:

[seq(seq(T[i-m, m], m=1..i-1), i=1..N+1)]; # Robert Israel, Sep 05 2016

CROSSREFS

Sequence in context: A141543 A182720 A146540 * A246180 A102057 A276276

Adjacent sequences:  A162919 A162920 A162921 * A162923 A162924 A162925

KEYWORD

nonn,tabl

AUTHOR

Leroy Quet, Jul 17 2009

EXTENSIONS

More terms from Robert Israel, Sep 05 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified December 12 01:57 EST 2019. Contains 329948 sequences. (Running on oeis4.)