A075481 Number of iteration that first becomes smaller than the initial value if Collatz-function (A006370) is iterated, starting with numbers of form 64n+47. Corresponds to selection of every 16th term from A074474.

89, 51, 14, 33, 22, 17, 14, 45, 27, 22, 14, 35, 17, 20, 14, 35, 22, 22, 14, 43, 22, 17, 14, 27, 128, 20, 14, 25, 17, 25, 14, 20, 22, 30, 14, 82, 20, 17, 14, 45, 22, 27, 14, 25, 17, 27, 14, 48, 20, 30, 14, 43, 30, 17, 14, 58, 61, 27, 14, 53, 17, 56, 14, 22, 30, 58, 14, 27, 53

Offset: 0

Author

Labos Elemer, Sep 23 2002

Keywords

• nonn

Comments

Remark that initial values of form 64m+r, if r={3,11,19,27,35,43,51,55} provide first-sink-lengths {7,9,7,9,7,9,7,9} respectively; e.g. {64k+19,192k+58,96k+29,288k+88,144k+44,72k+22,36k+11} submerge first below initial value at the 7th term,36k+11<64k+19.

Examples

			n=2: 64n+47=175,list={175,526,263,790,395,1186,593,1780, 890,445,1336,668,334,167,502,251....}, i.e. the 14th term=167 is the first that <175, the initial value, so a(2)=14.
		

Crossrefs

Cf. A074473, A074474, A075476-A075483, A006370.

Formula

a(n)=A075473[64n+47], n=0, ..., 256