Wikipedia:Reference desk/Archives/Mathematics/2016 October 10

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October 10

Name for such progressions

What is the name of a progression where there are two or more ratios which alternate every step.

E.g., two ratios 5 and 2

1,5,10,50,100,500,1000,5000,10000,...

Three ratios 5, 2, 10

1,5,10,100,500,1000,10000,...

Or 2, 5, 10

1,2,10,100,200,1000,10000,...

Or 2, 3, 5, 10

1,2,6,30,300,600,1800,9000,90000,...

--Lüboslóv Yęzýkin (talk) 06:39, 10 October 2016 (UTC)

I don't know a name for such progressions, but they are geometric progressions added together:

(1, 10, 100, 1000, ... ...) + (5, 50, 500, 5000, ... ...)

Dolphin (t) 11:25, 10 October 2016 (UTC)

Interleave sequence. -- ToE 12:17, 10 October 2016 (UTC)

Well, it's a specific kind of interleave sequence. And for the ones with three or more ratios, it's a generalization of that, if the article's definition is complete. --69.159.61.230 (talk) 18:32, 10 October 2016 (UTC)

Preferred number. Bo Jacoby (talk) 05:40, 11 October 2016 (UTC).