A380371 a(n) is the integer part of the area of a rhombus with side n and angle n degrees.

0, 0, 0, 0, 1, 2, 3, 5, 8, 12, 17, 23, 29, 38, 47, 58, 70, 84, 100, 117, 136, 158, 181, 206, 234, 264, 296, 330, 368, 407, 450, 494, 542, 593, 646, 702, 761, 823, 889, 957, 1028, 1102, 1180, 1261, 1344, 1431, 1522, 1615, 1712, 1812, 1915, 2021, 2130, 2243, 2359

Offset: 0

Author

Nicolay Avilov, Jan 23 2025

Keywords

• nonn
• easy
• fini
• full

Comments

The angle n ranges 0 to 180 inclusive.

Terms increase to a maximum 12951 at n = 131 and then decrease.

Examples

			a(30) = 30*30*sin(30 degrees) = 450.
a(90) = 8100 is the area of a square with a side of 90.
		

Links

• Nicolay Avilov, Table of n, a(n) for n = 0..180

Formula

a(n) = floor(n^2*sin(Pi*n/180)).