A207852 Smallest number m such that there are exactly n ways to partition the numbers {1,...,m} into nonempty sets P and S with the product of the elements of P equal to the sum of elements in S.

1, 3, 12, 10, 19, 26, 33, 39, 55, 74, 48, 62, 71, 99, 45, 140, 96, 176, 104, 144, 159, 175, 230, 191, 320, 328, 240, 334, 259, 344, 279, 308, 303, 505, 419, 560, 714, 550, 455, 665, 684, 670, 751, 935, 899, 800, 1051, 776, 928, 602, 749, 1104, 689, 1295, 1364

Offset: 0

Author

Reinhard Zumkeller, Feb 21 2012

Keywords

• nonn

Comments

A178830(a(n)) = n and A178830(m) <> n for m < a(n).

Examples

			a(1) =  3: 3 = 1+2;
a(2) = 12: 1*5*12 = 2+3+4+6+7+8+9+10+11, 2*4*8 = 1+3+5+6+7+9+10+11+12;
a(3) = 10: 1*2*3*7 = 4+5+6+8+9+10, 1*4*10 = 2+3+5+6+7+8+9, 6*7 = 1+2+3+4+5+8+9+10.
		

Programs

Haskell

import Data.List (elemIndex)
import Data.Maybe (fromJust)
a207852 n = (fromJust $ elemIndex n a178830_list) + 1

Extensions

a(25)-a(54) from Alois P. Heinz, Jun 07 2012