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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). 0
4, 6, 12, 60, 5040, 293318625600 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

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.

Cf. A009287. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 26 2010]

Sequence in context: A050537 A114413 A068507 * A061072 A130435 A028444

Adjacent sequences:  A133451 A133452 A133453 * A133455 A133456 A133457

KEYWORD

fini,full,nonn

AUTHOR

Lekraj Beedassy (blekraj(AT)yahoo.com), Dec 22 2007

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Last modified February 15 09:54 EST 2012. Contains 205763 sequences.