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A165430 Table T(n,m) read by rows: the greatest common unitary divisor of n and m, n>=1, 1<=m<=n. 2
1, 1, 2, 1, 1, 3, 1, 1, 1, 4, 1, 1, 1, 1, 5, 1, 2, 3, 1, 1, 6, 1, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 1, 1, 8, 1, 1, 1, 1, 1, 1, 1, 1, 9, 1, 2, 1, 1, 5, 2, 1, 1, 1, 10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 11, 1, 1, 3, 4, 1, 3, 1, 1, 1, 1, 1, 12, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 13, 1, 2, 1, 1, 1, 2, 7, 1, 1, 2, 1, 1 (list; table; graph; refs; listen; history; internal format)
OFFSET

1,3

COMMENTS

The maximum number which appears in row n and also in row m of A077610. The sequence of the counts of 1 in row n=1,2,3,... is 1, 1, 2, 3, 4, 3, 6, 7, 8, 6, 10, 8, 12, 9, 9,...

LINKS

Pentti Haukkanen, On a gcd-sum function, Aeuqat. Math. 76 (1-2) (2008) 168-178.

EXAMPLE

The table starts

1;

1,2

1,1,3

1,1,1,4

1,1,1,1,5

1,2,3,1,1,6

1,1,1,1,1,1,7

1,1,1,1,1,1,1,8

1,1,1,1,1,1,1,1,9

1,2,1,1,5,2,1,1,1,10

MAPLE

A077610 := proc(n) local a; a := {} ; for d in numtheory[divisors](n) do if gcd(d, n/d) = 1 then a := a union {d} ; fi; od: a; end: gcud := proc(n, m) local cud ; cud := A077610(n) intersect A077610(m) ; max(op(cud)) ; end: seq(seq(gcud(n, m), m=1..n), n=1..20) ;

CROSSREFS

Cf. A034444.

Sequence in context: A127949 A167407 A051340 * A164823 A167269 A105535

Adjacent sequences:  A165427 A165428 A165429 * A165431 A165432 A165433

KEYWORD

easy,nonn,tabl

AUTHOR

R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Sep 18 2009

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Last modified February 15 05:09 EST 2012. Contains 205694 sequences.