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A139547 Triangle read by rows: T(n,k) = A003418(A010766). +0
6
1, 2, 1, 6, 1, 1, 12, 2, 1, 1, 60, 2, 1, 1, 1, 60, 6, 2, 1, 1, 1, 420, 6, 2, 1, 1, 1, 1, 840, 12, 2, 2, 1, 1, 1, 1, 2520, 12, 6, 2, 1, 1, 1, 1, 1, 2520, 60, 6, 2, 2, 1, 1, 1, 1, 1, 27720, 60, 6, 2, 2, 1, 1, 1, 1, 1, 1, 27720, 60, 12, 6, 2, 2, 1, 1, 1, 1, 1, 1, 360360, 60, 12, 6, 2, 2, 1, 1, 1, 1, 1 (list; table; graph; listen)
OFFSET

0,2

COMMENT

This triangle fits the formula of I. Vardi in the Mathworld link about the von Mangoldt function. That formula is the basis for Chebyshev's estimate for the number of primes.

REFERENCES

I. Vardi, Computational Recreations in Mathematica. Addison-Wesley, Redwood City, CA, 1991, p. 155.

LINKS

Weisstein, Eric W, Mangoldt Function..

EXAMPLE

Triangle begins:

1;

2,1;

6,1,1;

12,2,1,1;

60,2,1,1,1;

60,6,2,1,1,1;

420,6,2,1,1,1,1;

840,12,2,2,1,1,1,1;

2520,12,6,2,1,1,1,1,1;

2520,60,6,2,2,1,1,1,1,1;

27720,60,6,2,2,1,1,1,1,1,1;

27720,60,12,6,2,2,1,1,1,1,1,1;

360360,60,12,6,2,2,1,1,1,1,1,1,1;

...

CROSSREFS

Cf. A000142, A010766, A014963, A003418, A139550, A139552, A139554.

Sequence in context: A060480 A094673 A089808 this_sequence A126342 A082388 A085099

Adjacent sequences: A139544 A139545 A139546 this_sequence A139548 A139549 A139550

KEYWORD

nonn,tabl

AUTHOR

Mats Granvik (mgranvik(AT)abo.fi), Apr 27 2008, May 07 2008

EXTENSIONS

Edited by Mats Granvik (mats.granvik(AT)abo.fi), Jun 28 2009

Further edits from N. J. A. Sloane, Jul 03 2009

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Last modified December 7 08:40 EST 2009. Contains 170430 sequences.


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