A214206 a(n) = largest m such that m*(m+1)/2 <= 14*n.

0, 4, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 17, 18, 19, 20, 20, 21, 21, 22, 23, 23, 24, 24, 25, 25, 26, 27, 27, 28, 28, 28, 29, 29, 30, 30, 31, 31, 32, 32, 32, 33, 33, 34, 34, 35, 35, 35, 36, 36, 36, 37, 37, 38, 38, 38, 39, 39, 39, 40, 40, 40, 41, 41, 41, 42, 42, 42, 43, 43, 43, 44, 44, 44, 45, 45, 45, 45, 46, 46, 46, 47, 47, 47, 48, 48, 48, 48, 49, 49, 49, 49, 50

Offset: 0

Author

N. J. A. Sloane, Jul 08 2012

Keywords

• nonn

Comments

Created in an attempt to simplify the definition of certain sequences currently under review by the editors.

Examples

			4*5/2 <= 14 but 5*6/2 > 14, so a(1)=4.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000

Programs

Mathematica

Array[Floor[(Sqrt[1+112#]-1)/2]&,100,0] (* Harvey P. Dale, Dec 22 2012 *)

Formula

a(n) = A003056(14*n). - R. J. Mathar, Jul 09 2012