A056610 - OEIS

A056610

Quotient: squarefree kernel of lcm(1,..,n) (or of n!) divided by kernel of central binomial coefficient.

1, 1, 2, 1, 3, 3, 6, 3, 5, 5, 5, 5, 35, 35, 14, 7, 21, 21, 105, 105, 55, 55, 165, 165, 429, 429, 1001, 1001, 1001, 1001, 2002, 1001, 1547, 1547, 221, 221, 4199, 4199, 323, 323, 2261, 2261, 24871, 24871, 572033, 572033, 572033, 572033, 408595, 408595

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OFFSET

1,3

LINKS

Table of n, a(n) for n=1..50.

FORMULA

a(n) = A007947(A000142(n))/A007947(A001405(n)) = A034386(n)/A048633(n).

EXAMPLE

n = 10, lcm(1, 2, 3, ..., 10) = 2520, lcm(1, 10, 45, 120, 210, 252) = 252; the corresponding kernels are 210 or 42. The quotient is a(10) = 5.

CROSSREFS

Cf. A003418, A000142, A034386, A007947, A001405, A048633.

Sequence in context: A132888 A213934 A124774 * A341450 A343381 A336096

Adjacent sequences: A056607 A056608 A056609 * A056611 A056612 A056613

KEYWORD

nonn

AUTHOR

Labos Elemer, Aug 07 2000

STATUS

approved