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A015638 Number of ordered quadruples of integers from [ 2,n ] with no global factor. 0
0, 3, 9, 28, 50, 105, 169, 279, 406, 625, 839, 1202, 1570, 2086, 2646, 3461, 4219, 5358, 6452, 7899, 9381, 11404, 13240, 15805, 18272, 21383, 24461, 28520, 32107, 37066, 41706, 47395, 52968, 59990, 66312, 74747, 82553, 91969, 100989, 112468 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

Table of n, a(n) for n=2..41.

CROSSREFS

Sequence in context: A175129 A102558 A022767 * A032092 A026524 A282081

Adjacent sequences:  A015635 A015636 A015637 * A015639 A015640 A015641

KEYWORD

nonn

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified May 29 15:44 EDT 2020. Contains 334704 sequences. (Running on oeis4.)