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A139547 Square array of lcm sequences read by upwards antidiagonals, in which row products give the factorials. +0
5
1, 1, 1, 2, 1, 1, 6, 1, 1, 1, 12, 1, 1, 1, 1, 60, 2, 1, 1, 1, 1, 60, 2, 1, 1, 1, 1, 1, 420, 6, 1, 1, 1, 1, 1, 1, 840, 6, 2, 1, 1, 1, 1, 1, 1, 2520, 12, 2, 1, 1, 1, 1, 1, 1, 1, 2520, 12, 2, 1, 1, 1, 1, 1, 1, 1, 1, 27720, 60, 6, 2, 1, 1, 1, 1, 1, 1, 1, 1, 27720, 60, 6, 2, 1, 1, 1, 1, 1, 1, 1, 1, 1 (list; table; graph; listen)
OFFSET

0,4

COMMENT

This table seems to fit the formula of I. Vardi given in equation (11) in the Mathworld section about the von Mangoldt Function. The first columns are A003418, A139550, A139552, A139554.

REFERENCES

A. Granville and G. Martin, Prime number races, Amer. Math. Monthly, 113 (No. 1, 2006), p. 10-11.

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

LINKS

Weisstein, Eric W, Mangoldt Function..

FORMULA

T(n,k) = if n>=k then A003418((A120885-1)) else 1.

EXAMPLE

Beginning of array and row products:

1 1 1 1 1 1 1 1 1 ... = 1

1 1 1 1 1 1 1 1 1 ... = 1

2 1 1 1 1 1 1 1 1 ... = 2

6 1 1 1 1 1 1 1 1 ... = 6

12 2 1 1 1 1 1 1 1 ... = 24

60 2 1 1 1 1 1 1 1 ... = 120

60 6 2 1 1 1 1 1 1 ... = 720

420 6 2 1 1 1 1 1 1 ... = 5040

840 12 2 2 1 1 1 1 1 ... = 40320

...

CROSSREFS

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

Cf. A120885.

Adjacent sequences: A139544 A139545 A139546 this_sequence A139548 A139549 A139550

Sequence in context: A036563 A025264 A139622 this_sequence A096162 A053383 A125731

KEYWORD

nonn,tabl

AUTHOR

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

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Last modified October 6 16:13 EDT 2008. Contains 144667 sequences.


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