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A065737
Largest square <= binomial(n,2).
1
0, 1, 1, 4, 9, 9, 16, 25, 36, 36, 49, 64, 64, 81, 100, 100, 121, 144, 169, 169, 196, 225, 225, 256, 289, 324, 324, 361, 400, 400, 441, 484, 484, 529, 576, 625, 625, 676, 729, 729, 784, 841, 900, 900, 961, 1024, 1024, 1089, 1156, 1225, 1225, 1296, 1369, 1369, 1444
OFFSET
1,4
LINKS
FORMULA
a(n) = A048760(binomial(n,2)).
a(n) = A061288(n-1)^2 = A000290(A061288(n-1)) for n>=2. - Alois P. Heinz, Nov 07 2024
MATHEMATICA
Floor[Sqrt[#]]^2&/@Binomial[Range[50], 2] (* Harvey P. Dale, Feb 28 2020 *)
PROG
(PARI) a(n) = { sqrtint(binomial(n, 2))^2 } \\ Harry J. Smith, Oct 28 2009
KEYWORD
easy,nonn
AUTHOR
Labos Elemer, Nov 15 2001
STATUS
approved