OFFSET
1,4
FORMULA
a(n) = ((n-1)^(n+1) + (-1)^n*(n+1)^(n-1))/(n^2).
MATHEMATICA
Table[((m-1)^(m+1)+(-1)^m*(m+1)^(m-1))/(m^2), {m, 1, 20}]
PROG
(PARI) a(n) = ((n-1)^(n+1) + (-1)^n*(n+1)^(n-1))/n^2; \\ Michel Marcus, Jun 06 2021
CROSSREFS
KEYWORD
sign
AUTHOR
Alexander Adamchuk, Dec 22 2013
STATUS
approved