A133454 - OEIS

A133454

Chain of 6 highly composite numbers generated when subject to the recurrence relation tau(a(n+1)) = a(n), with a(0)=3, where tau(n) is the number-of-divisors function A000005(n).

4, 6, 12, 60, 5040, 293318625600

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OFFSET

1,1

COMMENTS

We omit the seed a(0) from the sequence and keep the offset at 1, because 3 is not highly composite. - R. J. Mathar, Jun 20 2021

LINKS

Table of n, a(n) for n=1..6.

EXAMPLE

Since 4 is the HCN with 3 divisors, we have tau(4) = 3 and therefore a(1)=4; the HCN with 4 divisors is 6, so that tau(6) = 4 and hence a(2)=6; the HCN with 6 divisors is 12 so that tau(12) = 6, implying a(3)=12, ...

CROSSREFS

Cf. A002182.

A finite subsequence of A009287.

Sequence in context: A050537 A114413 A068507 * A061072 A130435 A028444

Adjacent sequences: A133451 A133452 A133453 * A133455 A133456 A133457

KEYWORD

fini,full,nonn

AUTHOR

Lekraj Beedassy, Dec 22 2007

STATUS

approved