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

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A130071 Triangle, A007444(k) in each column interspersed with k zeros. 2
2, 2, 1, 2, 0, 3, 2, 1, 0, 4, 2, 0, 0, 0, 9, 2, 1, 3, 0, 0, 7, 2, 0, 0, 0, 0, 0, 15, 2, 1, 0, 4, 0, 0, 0, 12, 2, 0, 3, 0, 0, 0, 0, 0, 18, 2, 1, 0, 0, 9, 0, 0, 0, 0, 17 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Row sums = the primes. T(n,k) = 0 if k does not divide n. If k divides n, extract A007444(k) which become the nonzero terms of row n, sum = n-th prime. Example: The factors of 6 are (1, 2, 3 and 6) = k's for A007444(k) = (2 + 1 + 3 + 7) = p(6) = 13. A007444 = the Moebius transform of the primes, (2, 1, 3, 4, 9, 7, 15, 12,...), as the right diagonal of A130071.

LINKS

Table of n, a(n) for n=1..55.

FORMULA

Given the Moebius transform of the primes, A007444: (2, 1, 3, 4, 9, 7, 15,...), the k-th term (k= 1,2,3,...) of this sequence generates the k-th column of A130071, interspersed with (k-1) zeros.

EXAMPLE

First few rows of the triangle are:

2;

2, 1;

2, 0, 3;

2, 1, 0, 4;

2, 0, 0, 0, 9;

2, 1, 3, 0, 0, 7;

2, 0, 0, 0, 0, 0, 15;

2, 1, 0, 4, 0, 0, 0, 12;

2, 0, 3, 0, 0, 0, 0, 0, 18;

2, 1, 0, 0, 9, 0, 0, 0, 0, 17;

...

CROSSREFS

Cf. A130070, A007444, A054525, A000040.

Sequence in context: A089077 A203398 A225064 * A321373 A305615 A038540

Adjacent sequences:  A130068 A130069 A130070 * A130072 A130073 A130074

KEYWORD

nonn,tabl

AUTHOR

Gary W. Adamson, May 05 2007

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 November 17 00:08 EST 2019. Contains 329209 sequences. (Running on oeis4.)