A133411 Smallest highly composite number of the form k*a(n-1) where k is an integer greater than 1.

1, 2, 4, 12, 24, 48, 240, 720, 5040, 10080, 20160, 221760, 665280, 8648640, 17297280, 294053760, 5587021440, 27935107200, 642507465600, 1927522396800, 13492656777600, 26985313555200, 782574093100800, 24259796886124800

Offset

1,2

Comments

Conjecture: subsequence of A019505.

Links

Antti Karttunen, Table of n, a(n) for n = 1..223 (computed from the 10000 term b-file of A002182 prepared from Flammenkamp's data)

Example

6 is not in the sequence because 6 is not a multiple of 4, the previous term.

Prog

(PARI)
sublist_of_first_proper_multiple_terms_of(v) = { my(u=v[1], lista=List(u)); for(i=2, #v, if((v[i]>u)&&!(v[i]%u), u = v[i]; listput(lista, u))); Vec(lista); };
v133411 = sublist_of_first_proper_multiple_terms_of(v002182); \\ v002182 contains the terms of A002182.
A133411(n) = v133411[n]; \\ Antti Karttunen, Jan 10 2020

Crossrefs

Cf. A002182, A019505, A328521, A330744 (primorial deflation).

Sequence in context: A348092 A343458 A328521 * A201078 A004645 A045687

Adjacent sequences: A133408 A133409 A133410 * A133412 A133413 A133414

Keyword

nonn

Author

J. Lowell, Nov 25 2007

Extensions

a(12)-a(24) from Donovan Johnson, Sep 09 2008

Status

approved