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A129649 Largest order of a permutation of n elements with exactly 4 cycles. Also the largest LCM of a 4-partition of n. 4
0, 0, 0, 1, 2, 3, 6, 6, 12, 15, 30, 30, 60, 60, 84, 105, 210, 140, 420, 210, 330, 420, 840, 420, 1260, 1155, 1540, 1365, 2520, 1320, 3080, 3465, 3960, 4095, 5544, 5005, 6930, 6435, 8190, 9009, 10296, 8415, 12870, 11781, 13464, 15015, 18018, 17017, 20592, 21879 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

a(n) is asymptotic to (n^4)/256.

LINKS

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

EXAMPLE

a(18)=140 because 18 = 7+5+2+2 and lcm(2,2,5,7) = 140 is maximal.

MATHEMATICA

Max[LCM @@@ Compositions[ #, 4]] & /@ Range[1, n] (* needs Combinatorica *)

Join[{0, 0, 0}, Table[Max[LCM@@#&/@IntegerPartitions[n, {4}]], {n, 4, 50}]] (* Harvey P. Dale, Feb 25 2012 *)

CROSSREFS

Cf. A000793, A129647, A129648, A129650, A129651.

Sequence in context: A346758 A143177 A129648 * A129650 A319055 A339546

Adjacent sequences:  A129646 A129647 A129648 * A129650 A129651 A129652

KEYWORD

nonn

AUTHOR

Nickolas Reynolds (nickels(AT)gmail.com), Apr 25 2007

STATUS

approved

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Last modified September 20 08:10 EDT 2021. Contains 347577 sequences. (Running on oeis4.)