A152623 Decimal expansion of 3/2.

1, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 1

Author

N. J. A. Sloane, Oct 30 2009

Keywords

• nonn
• cons
• easy

Comments

Sum of the inverses of the tetrahedral numbers (A000292). - Michael B. Porter, Nov 27 2017

For any triangle ABC, cos A + cos B + cos C <= 3/2; equality is obtained only when the triangle is equilateral (see the Kiran S. Kedlaya link). - Bernard Schott, Sep 17 2022

Examples

			1.5000000000000000000000000000000000000000000000000000000000...
		

Links

• Kiran S. Kedlaya, A < B, (1999), Problem 6.2, p. 6.
• Index entries for linear recurrences with constant coefficients, signature (1).

Crossrefs

Cf. A000292 (tetrahedral numbers).

Sums of inverses: A002117 (cubes), A175577 (octahedral numbers), A295421 (dodecahedral numbers), A175578 (icosahedral numbers).

Cf. A002194, A020821, A104956 (other trigonometric inequalities).

Programs

PARI

3/2. \\ Charles R Greathouse IV, Jan 10 2022