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A112790 Array where a(1,1)=1 and m-th term of n-th row is number of terms of (n-1)th row which are coprime to the m-th divisor of n. 1
1, 1, 1, 2, 2, 2, 0, 0, 3, 1, 2, 2, 1, 1, 4, 4, 2, 0, 0, 0, 4, 1, 1, 3, 2, 3, 2, 4, 4, 2, 0, 2, 0, 0, 0, 6, 2, 2, 0, 2, 0, 4, 2, 2, 2, 4, 0, 0, 0, 0, 5, 1, 2, 2, 2, 2, 2, 2, 6, 6, 2, 0, 0, 2, 0, 0, 6, 2, 2, 2, 4, 0, 4, 0, 4, 2, 2, 0, 2, 0, 0, 0, 0, 0, 8, 2, 2, 3, 0, 3, 0, 4, 0, 0, 0, 4, 0, 0, 1, 0, 0, 6, 2, 2, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Number of terms in row n is A000005(n).

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

The irregular array's 5th row is [3,1]. The divisors of 6 are 1, 2, 3 and 6. In the 5th row there are 2 terms coprime to 1, 2 terms coprime to 2, 1 term coprime to 3 and 1 term coprime to 6. So the 6th row of the array is [2,2,1,1].

Array starts

1;

1,1;

2,2;

2,0,0;

3,1;

2,2,1,1;

4,4;

2,0,0,0;

CROSSREFS

Cf. A000005, A112791.

Sequence in context: A262048 A034852 A212438 * A179835 A110857 A108867

Adjacent sequences:  A112787 A112788 A112789 * A112791 A112792 A112793

KEYWORD

nonn,tabf

AUTHOR

Leroy Quet, Dec 31 2005

EXTENSIONS

More terms from R. J. Mathar, Aug 29 2007

STATUS

approved

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Last modified October 19 02:23 EDT 2018. Contains 316327 sequences. (Running on oeis4.)