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A152453 Where records in occur in A152235. 2
1, 2, 4, 12, 48, 144, 576, 720, 2880, 25920, 129600, 414720, 907200, 14515200, 58060800, 130636800, 522547200, 3265920000, 13063680000, 22861440000, 91445760000, 251475840000, 1005903360000, 16094453760000, 64377815040000, 81478172160000, 1030045040640000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..87

EXAMPLE

First few terms of A152235 are 1, 2, 2, 3, 2, 2, 2, 2, 3, 2, 2, 6, so a(1) to a(4) are 1, 2, 4, 12.

PROG

(MAGMA) W:=[]; r:=0; for n in [1..1300000] do a:=&*PrimeDivisors(NumberOfDivisors(n)); if r lt a then r:=a; Append(~W, n); end if; end for; print W;

CROSSREFS

Cf. A152235 (largest squarefree number dividing the number of divisors of n), A152452 (records in A152235), A007947 (largest squarefree number dividing n).

Subsequence of A025487.

Sequence in context: A332235 A131387 A207647 * A277281 A172452 A004527

Adjacent sequences:  A152450 A152451 A152452 * A152454 A152455 A152456

KEYWORD

nonn

AUTHOR

Klaus Brockhaus, Dec 04 2008

EXTENSIONS

a(15)-a(20) from Donovan Johnson, Jul 30 2011

More terms from Amiram Eldar, Sep 01 2019

STATUS

approved

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Last modified July 13 10:38 EDT 2020. Contains 335687 sequences. (Running on oeis4.)