A060301 For n>3: a(n) is a multiple of three distinct earlier terms.

2, 3, 5, 30, 180, 300, 450, 1080, 1800, 2700, 3000, 4500, 6480, 6750, 10800, 16200, 18000, 27000, 30000, 38880, 40500, 45000, 64800, 67500, 97200, 101250, 108000, 162000, 180000, 233280, 243000, 270000, 300000, 388800, 405000, 450000, 583200

Offset: 1

Author

Henry Bottomley, Mar 28 2001

Keywords

• nonn

Examples

			a(15) = 10800 = 2*30*180 = a(1)*a(4)*a(5).
		

Links

• R. G. Wilson, V, Note, n.d.

Crossrefs

Cf. A000423.

Formula

a(n) is of the form 2^b*3^c*5^d where either b+c+d=1, or where each of b, c and d are positive and the largest of the three is an odd number less than the sum of the other two. For n>3: a(n) is 30 times a power of 6 times a power of 10 times a power of 15.