A135875 Multiply the positive divisors n in order (starting at 1). a(n) is the largest such partial product that is <= n.

1, 2, 3, 2, 5, 6, 7, 8, 3, 10, 11, 6, 13, 14, 15, 8, 17, 6, 19, 8, 21, 22, 23, 24, 5, 26, 27, 8, 29, 30, 31, 8, 33, 34, 35, 24, 37, 38, 39, 40, 41, 36, 43, 8, 15, 46, 47, 24, 7, 10, 51, 8, 53, 36, 55, 56, 57, 58, 59, 24, 61, 62, 21, 64, 65, 36, 67, 8, 69, 70, 71, 24, 73, 74, 15, 8, 77, 36, 79, 40

Offset

1,2

Links

Table of n, a(n) for n=1..80.

Example

The positive divisors of 12 are 1,2,3,4,6,12. Checking the partial products: 1=1, 1*2=2, 1*2*3=6, 1*2*3*4=24, 1*2*3*4*6 = 144, 1*2*3*4*6*12 = 1728. 6 is the largest such product that is <= 12. So a(12) = 6.

Prog

(PARI) for(n=1, 80, d=divisors(n); L=numdiv(n); T=1; i=1; while(i<=L&&T*d[i]<=n, T*=d[i]; i++); print1(T", "))

Crossrefs

Cf. A135874.

Sequence in context: A110500 A161871 A331737 * A372379 A350390 A366765

Adjacent sequences: A135872 A135873 A135874 * A135876 A135877 A135878

Keyword

nonn

Author

Leroy Quet, Dec 03 2007

Extensions

More terms from Robert Gerbicz, Nov 26 2010

Status

approved