OFFSET
1,2
FORMULA
a(n) = A023811(2n)/(2n-1). [Corrected by Alexander R. Povolotsky, Oct 15 2022]
a(n) = A221741(2n-1). - Alexander R. Povolotsky, Oct 15 2022
PROG
(PARI) f(n) = (n^n-n^2)\(n-1)^2+1; \\ A023811
a(n) = f(2*n)/(2*n-1); \\ Michel Marcus, Oct 16 2022
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Antti Karttunen, Dec 13 1999
EXTENSIONS
a(13) and a(14) added by Alexander R. Povolotsky, Oct 16 2022
STATUS
approved