A001041 a(0)=12; thereafter a(n) = 12 times the product of the first n primes.

12, 24, 72, 360, 2520, 27720, 360360, 6126120, 116396280, 2677114440, 77636318760, 2406725881560, 89048857617720, 3651003162326520, 156993135980040360, 7378677391061896920, 391069901726280536760, 23073124201850551668840

Offset: 0

Author

Bob Marshall, 1811 California St., Eureka CA 95501

Keywords

• nonn
• easy

Comments

Bob Marshall calls these the "holotomic numbers" and opines: "This sequence, aptly designated as the Holotomic Sequence, represents the minimal plural quantities that accommodate the maximum amount of consecutive factors." Thus this can be seen as a version of A051451. - Charles R Greathouse IV, Jan 12 2012

If we were to take the maximum number of consecutive factors as the definition, the sequence would be prefixed with 1, 2, 6. - Franklin T. Adams-Watters, Jun 13 2015

Links

• T. D. Noe, Table of n, a(n) for n = 0..100
• R. K. Guy, Letters to N. J. A. Sloane, June-August 1968
• Index to divisibility sequences

Crossrefs

Equals 12 * A002110.

Programs

Magma

[12] cat [12*&*[NthPrime(i):i in [1..n]]:n in [1..17]]; // Marius A. Burtea, Feb 11 2020

Mathematica

12*FoldList[ #1*Prime[ #2 ]&, 1, Range[ 20 ] ]

PARI

a(n)=12*prod(i=1,n,prime(i)); \\ Charles R Greathouse IV, Jan 12 2012

Extensions

More terms from James Sellers, Sep 19 2000