A154130 Exponents m with decreasing fractional part of (4/3)^m.

1, 4, 13, 17, 128, 485, 692, 1738, 12863, 77042, 109705, 289047, 720429, 4475944, 75629223, 182575231

Offset: 1

Author

Hieronymus Fischer, Jan 11 2009

Keywords

• nonn

Comments

The next term is greater than 3*10^8.

Examples

			a(3)=13, since fract((4/3)^13)=0.0923.., but fract((4/3)^k)>=0.16... for 1<=k<=12; thus fract((4/3)^13)<fract((4/3)^k) for 1<=k<13.
		

Crossrefs

Cf. A081464, A153669, A153701, A153708, A154138, A154146.

Cf. A002379, A064628.

Formula

Recursion: a(1):=1, a(k):=min{ m>1 | fract((4/3)^m) < fract((4/3)^a(k-1))}, where fract(x) = x-floor(x).

Extensions

Extended by Charles R Greathouse IV, Nov 03 2009

a(15)-a(16) from Robert Gerbicz, Nov 21 2010