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URL: https://oeis.org/A142972

⇱ A142972 - OEIS

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A142972
a(n) = the largest integer such that each positive integer <= a(n) divides at least one integer k, where the n-th prime <= k <= the (n+1)th prime.
2
3, 5, 3, 5, 4, 5, 3, 5, 9, 3, 9, 5, 3, 5, 8, 9, 6, 9, 5, 4, 7, 5, 8, 10, 5, 3, 5, 4, 5, 15, 5, 9, 3, 14, 3, 9, 10, 5, 10, 8, 6, 11, 4, 5, 3, 17, 13, 5, 4, 5, 7, 6, 11, 9, 7, 8, 3, 8, 5, 3, 13, 21, 5, 4, 5, 20, 9, 11, 4, 5, 7, 15, 10, 9, 5, 9, 15, 5, 9, 11, 7, 11, 4, 7, 5, 8, 13, 5, 3, 5, 14, 13, 5, 9, 5
OFFSET
1,1
COMMENTS
a(n) = A142973(n) - 1.
EXAMPLE
The 15th prime is 47 and the 16th prime is 53. So we will consider the integers 47,48,49,50,51,52,53. Now, 1 divides each of these 6 integers. 2 divides 48, 50 and 52. 3 divides 48 and 51. 4 divides 48 and 52. 5 divides 50. 6 divides 48. 7 divides 49. 8 divides 48. But 9 does not divide any integer that is between 47 and 53. So a(15)=8, since 1, 2, 3, 4, 5, 6, 7 and 8 each divide at least one integer between 47 and 53.
CROSSREFS
Cf. A142973.
Sequence in context: A094929 A096634 A105439 * A020765 A112756 A121795
KEYWORD
nonn
AUTHOR
Leroy Quet, Jul 14 2008
EXTENSIONS
Extended by Ray Chandler, Jun 21 2009
STATUS
approved