

A081472


a(n) = the smallest (n+k) such that the LCM of numbers from (n+1) to (n+k) is a multiple of n.


6



2, 4, 6, 8, 10, 9, 14, 16, 18, 15, 22, 16, 26, 21, 20, 32, 34, 27, 38, 25, 28, 33, 46, 32, 50, 39, 54, 35, 58, 35, 62, 64, 44, 51, 42, 45, 74, 57, 52, 48, 82, 49, 86, 55, 54, 69, 94, 64, 98, 75, 68, 65, 106, 81, 66, 64, 76, 87, 118, 65, 122, 93, 72, 128, 78, 77, 134, 85, 92, 77
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OFFSET

1,1


LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..1000


EXAMPLE

a(4) = 8 because lcm(5) = 5, lcm(5, 6) = 30 and lcm(5, 6, 7) = 210 are not divisible by 4, but lcm(5, 6, 7, 8) = 840 is.


MATHEMATICA

dv[n_]:=Module[{k=1}, While[!Divisible[LCM@@Range[n+1, n+k], n], k++]; k+n]; Array[dv, 70] (* Harvey P. Dale, Sep 13 2013 *)


CROSSREFS

Cf. A081467, A081468, A081469, A081470, A081471, A061243.
a(n) = n + A034699(n)
Sequence in context: A055952 A061243 A079431 * A097660 A238898 A176995
Adjacent sequences: A081469 A081470 A081471 * A081473 A081474 A081475


KEYWORD

nonn


AUTHOR

Amarnath Murthy, Mar 23 2003


EXTENSIONS

More terms from David Wasserman, Mar 24 2003


STATUS

approved



