login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A122414 Triangle T(n,k) for 1 <= k <= n read by rows, where T(n,k) = 1 if gcd(n,k) is prime, 0 otherwise. 2
0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

First column is all zeros, main diagonal is A010051 (characteristic function of primes).

LINKS

Table of n, a(n) for n=1..105.

PROG

(PARI) {m=14; v=vector(m, x, vector(x)); for(n=1, m, for(k=1, n, if(isprime(gcd(n, k)), v[n][k]=1))); for(n=1, m, for(k=1, n, print1(v[n][k], ", ")))}

CROSSREFS

Cf. A010051, A122415.

Row sums are in A117494. [From Klaus Brockhaus, May 29 2009]

Sequence in context: A272664 A074937 A143518 * A288216 A189628 A289239

Adjacent sequences:  A122411 A122412 A122413 * A122415 A122416 A122417

KEYWORD

nonn,tabl

AUTHOR

Klaus Brockhaus, Sep 03 2006

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 April 17 02:14 EDT 2021. Contains 343059 sequences. (Running on oeis4.)