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A057057
Let R(i,j) be the rectangle with antidiagonals 1; 2,3; 4,5,6; ...; C(n,3) is in antidiagonal a(n).
3
1, 3, 4, 6, 8, 11, 13, 15, 18, 21, 24, 27, 30, 33, 37, 40, 44, 48, 52, 55, 60, 64, 68, 72, 76, 81, 85, 90, 95, 100, 104, 109, 114, 119, 125, 130, 135, 141, 146, 152, 157, 163, 168, 174, 180, 186, 192, 198, 204, 210, 216, 223, 229
OFFSET
3,2
FORMULA
Round(sqrt(2*binomial(n, 3))). - Vladeta Jovovic, Jun 14 2003
MATHEMATICA
Table[Round[Sqrt[2*Binomial[n, 3]]], {n, 3, 60}] (* Harvey P. Dale, Nov 16 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jul 30 2000.
STATUS
approved