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A133008 The defining property of the sequences {A, B} = {A000028, A000379} is that they are the unique pair of sets complementary with respect to the positive integers such that p(n) = |{x : x, y in A, x < y, xy = n}| = |{x : x, y in B, x < y, xy = n}| for all n >= 1. The present sequence gives the values of p(n). 4
0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0, 2, 0, 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 2, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,48

LINKS

David W. Wilson, Table of n, a(n) for n = 1..10000

PROG

(Haskell)

a133008 n = length [x | x <- takeWhile (< n) a000028_list,

                    n `mod` x == 0, let y = n `div` x, x < y,

                    y `elem` takeWhile (<= n) a000028_list]

-- Reinhard Zumkeller, Oct 05 2011

CROSSREFS

Cf. A000028, A000379, A000069, A001969, A133009.

Sequence in context: A277017 A178498 A095408 * A102550 A293139 A213725

Adjacent sequences:  A133005 A133006 A133007 * A133009 A133010 A133011

KEYWORD

nonn

AUTHOR

David W. Wilson, Dec 21 2007

STATUS

approved

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Last modified December 12 03:27 EST 2018. Contains 318052 sequences. (Running on oeis4.)