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A177788
a(n) = binomial(n^2, n+1)/(n-1).
4
4, 63, 1456, 44275, 1669536, 75163011, 3934369216, 234799050915, 15736644960400, 1170354134607658, 95648578915114512, 8520904136405458044, 821828481957792579648, 85317719822978885714475, 9485883860726883646713600, 1124586875214241546178986915
OFFSET
2,1
COMMENTS
The entries are integer for n >= 2 because binomial(n^2,n+1)/(n-1) = n*binomial(n^2-2,n-1), which is a product of two integers.
LINKS
FORMULA
a(n) = binomial(n^2,n+1)/(n-1).
a(n) = n * A177234(n).
a(n) = n^2 * A177784(n).
MAPLE
n0:=30: T:=array(1..n0): T:=array(1..n0-1): for n from 2 to n0 do: T[n-1]:= (binomial(n^2, n+1))/(n-1): od: print(T):
MATHEMATICA
Table[Binomial[n^2, n+1]/(n-1), {n, 2, 40}] (* G. C. Greubel, Apr 28 2024 *)
PROG
(Magma) [Binomial(n^2, n+1)/(n-1): n in [2..30]]; // G. C. Greubel, Apr 28 2024
(SageMath) [binomial(n^2, n+1)/(n-1) for n in range(2, 31)] # G. C. Greubel, Apr 28 2024
(PARI) a(n) = binomial(n^2, n+1)/(n-1) \\ Charles R Greathouse IV, May 01 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
Michel Lagneau, May 13 2010
EXTENSIONS
Removed redundant second Maple version - R. J. Mathar, May 14 2010
STATUS
approved