OFFSET
0,2
COMMENTS
All primes between n^2 and (n+1)^2 divide a(n). No prime between (n+1)^2/2 and n^2 divides a(n). Every prime greater than n+1 has exponent 0 or 1 in the prime factorization of a(n). - T. D. Noe, Aug 09 2008
LINKS
T. D. Noe, Table of n, a(n) for n = 0..50
FORMULA
a(n) = binomial((n+1)^2, 2*n+1). - Gleb Ivanov, Mar 15 2022
MATHEMATICA
Binomial[#[[2]], #[[1]]]&/@Partition[Range[0, 20]^2, 2, 1] (* Harvey P. Dale, Jul 29 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Karol A. Penson, May 06 2002
EXTENSIONS
Better definition from Amarnath Murthy, Jul 14 2005
a(13) from Harvey P. Dale, Jul 29 2015
STATUS
approved