OFFSET
0,3
COMMENTS
Also, number of vector differences of two permutations of 1,2,...,n.
Number of distinct sums up to the order of components is given by A019589. - Max Alekseyev, Jun 19 2023
a(n) <= A362968(n). - Max Alekseyev, Jun 19 2023
EXAMPLE
The permutation sums for n=2 are (1,2) + (1,2) = (2,4); (1,2) + (2,1) = (2,1) + (1,2) = (3,3); (2,1) + (2,1) = (4,2); so a(2)=3.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
R. H. Hardin, Feb 28 2010
EXTENSIONS
a(0)=1 prepended by Alois P. Heinz, Jun 19 2023
a(11)-a(15) from Max Alekseyev, Jul 2 2023
STATUS
approved