OFFSET
1,1
FORMULA
a(n) = Sum_{i=1..n} A002503(i).
EXAMPLE
a(4) = 5 + 14 + 27 + 41 = 87.
MATHEMATICA
Accumulate[Select[Range[800], Divisible[Binomial[2#, #], (#+1)^2]&]] (* Harvey P. Dale, Apr 18 2011 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Jonathan Vos Post, Apr 15 2010
EXTENSIONS
Corrected by Harvey P. Dale, Apr 18 2011
STATUS
approved
