

A070829


Array showing which primes divide n >= 2.


1



1, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0
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OFFSET

2,1


COMMENTS

In the Kac reference this array is called rho_{p}(n) := 1 if p divides n else 0.
The row length sequence is A061395(n),n>=2: [1,2,1,3,2,4,1,2,3,5,2,6,4,3,...] (the index of the largest prime dividing n). All row entries beyond these numbers are 0, hence they are not shown. The n=1 row would have 0 for all entries.
The column sequences (without leading zeros) give for m>=1 periodic sequences with the period: 1 followed by p(m)1 zeros. They start with n=p(m) := A000040(m).


REFERENCES

Mark Kac, A Personal History of the Scottish Book, pp. 1727, in R. D. Mauldin (ed.), The Scottish Book, BirkhĂ¤user, Boston, Basel, 1981.


LINKS

Table of n, a(n) for n=2..82.
W. Lang, First 32 rows.


FORMULA

a(n, m)=1 if p(m), m>=1, divides n>=2, with the prime p(m) := A000040(m), else 0.


EXAMPLE

{1}, {0, 1}, {1}, {0, 0, 1}, {1, 1}, {0, 0, 0, 1}, {1}, {0, 1}, {1, 0, 1}...
Row n=10: {1,0,1} because p(1)=2 and p(3)= 5 divides 10.


CROSSREFS

Cf. A067255 (array with multiplicities).
Sequence in context: A168002 A267050 A267355 * A118175 A179762 A263804
Adjacent sequences: A070826 A070827 A070828 * A070830 A070831 A070832


KEYWORD

nonn,easy,tabf


AUTHOR

Wolfdieter Lang, May 17 2002


STATUS

approved



