A087085 Sum of the integer elements in the subsets of the subsets of the integers 1 to n.
0, 0, 2, 48, 3072, 2621440, 515396075520, 6198106008766409342976, 304893000761160863263183648258864317464576
Offset: 0
Examples
a(3)=48 since the 16 subsets of the sets ( ) (1) (2) (1,2) are ( ) (( )) ((1)) ((2)) ((1,2)) (( ) (1)) (( ) (2)) (( ) (1,2)) ((1) (2)) ((1) (1,2)) ((2) (1,2)) (( ) (1) (2)) (( ) (1) (1,2)) (( ) (2) (1,2)) ((1) (2) (1,2)) (( ) (1) (2) (1,2)) and the sum of the 32 integer elements is 48.
References
- Alan Sutcliffe, Divisors and Common Factors in Sets of Integers, awaiting publication.
Crossrefs
Formula
n*(n-1)*2^(n-4+2^(n-1))