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

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A122415 Triangle T(n,k) for 1 < k < n read by rows, where T(n,k) = 1 if gcd(n,k) is prime, 0 otherwise. 1
0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0 (list; table; graph; refs; listen; history; internal format)
OFFSET

3,1

COMMENTS

Triangle defined in A122414 without first column and main diagonal.

PROG

(PARI) {m=14; v=vector(m, x, vector(x)); for(n=1, m, for(k=1, n-1, if(isprime(gcd(n+2, k+1)), v[n][k]=1))); for(n=1, m, for(k=1, n, print1(v[n][k], ", ")))}

CROSSREFS

Cf. A122414.

Row sums are in A087625. [From Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), May 29 2009]

Sequence in context: A132151 A103588 A153638 * A109017 A110161 A134667

Adjacent sequences:  A122412 A122413 A122414 * A122416 A122417 A122418

KEYWORD

nonn,tabl

AUTHOR

Klaus Brockhaus (klaus-brockhaus(AT)t-online.de), Sep 03 2006

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 17 06:27 EST 2012. Contains 205998 sequences.