OFFSET
1,1
COMMENTS
See A339228 for additional details.
EXAMPLE
In the following examples elements in series are juxtaposed and elements in parallel are separated by '|'.
a(1) = 2: (1), (2).
a(2) = 7: (11), (12), (21), (22), (1|1), (1|2), (2|2).
PROG
(PARI) \\ See A339228 for R(n, k).
seq(n) = {R(n, 2)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Andrew Howroyd, Nov 28 2020
STATUS
approved