Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A143655
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A143655 Triangle read by rows, primes not dividing n; A054521 * (A061397 * 0^(n-k)), 1<=k<=n. +0
2
0, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 2, 3, 0, 0, 0, 0, 0, 0, 5, 0, 0, 2, 3, 0, 5, 0, 0, 0, 0, 3, 0, 5, 0, 7, 0, 0, 2, 0, 0, 5, 0, 7, 0, 0, 0, 0, 3, 0, 0, 0, 7, 0, 0, 0, 0, 2, 3, 0, 5, 0, 7, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 7, 0, 0, 0, 11, 0, 0, 2, 3, 0, 5, 0, 7, 0, 0, 0, 11, 0, 0, 0, 0, 3, 0, 5, 0, 0, 0, 0, 0, 11, 0 (list; table; graph; listen)
OFFSET

1,5

COMMENT

Row sums = A066911: (0, 0, 2, 3, 5, 5, 10, 15, 14,....)

FORMULA

Triangle read by rows, A054521 * (A061397 * 0^(n-k)), 1<=k<=n. T(n,k) = prime if k is prime but does not divide n. A054521 = a triangle with row sums phi(n). A061397 = (0, 2, 3, 0, 5, 0, 7,...)

EXAMPLE

First few rows of the triangle =

0;

0, 0;

0, 2, 0;

0, 0, 3, 0;

0, 2, 3, 0, 0;

0, 0, 0, 0, 5, 0;

0, 2, 3, 0, 5, 0, 0;

0, 0, 3, 0, 5, 0, 7, 0;

...

Row 8 has 3 primes < 8 not dividing 8: (3, 5, 7); where (3 + 5 + 7) = A066911(8).

CROSSREFS

Cf. A061397, A066911, A054521.

Sequence in context: A091227 A035444 A152489 this_sequence A076849 A083059 A046268

Adjacent sequences: A143652 A143653 A143654 this_sequence A143656 A143657 A143658

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson (qntmpkt(AT)yahoo.com), Aug 28 2008

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 25 20:09 EST 2009. Contains 167514 sequences.


AT&T Labs Research