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

0,3

References

Alan Sutcliffe, Divisors and Common Factors in Sets of Integers, awaiting publication.

Links

Table of n, a(n) for n=0..8.

Formula

n*(n-1)*2^(n-4+2^(n-1))

Example

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.

Crossrefs

A001146 gives the number of subsets of the subsets of the integers 1 to n. A028369 gives the number of subset elements in the subsets of the subsets of the integers 1 to n. A087084 gives the number of integer elements in the subsets of the subsets of the integers 1 to n.

Sequence in context: A322750 A367537 A346019 * A067626 A053071 A238838

Adjacent sequences: A087082 A087083 A087084 * A087086 A087087 A087088

Keyword

easy,nonn

Author

Alan Sutcliffe (alansut(AT)ntlworld.com), Aug 13 2003

Status

approved