OFFSET
-1,2
COMMENTS
There exists a set of Ramanujan-Sato series using this sequence.
Also a(n)=A002420(n+1)^2.
LINKS
Wikipedia, Ramanujan-Sato series.
MATHEMATICA
Table[(2*CatalanNumber[n])^2, {n, -1, 20}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ralf Steiner, Mar 28 2017
STATUS
approved