# Word for things separated by one, i.e. next to consecutive

I'm looking for a word that describes things which are not consecutive, but are separated by one item.

For example, 1,2,3,4 are consecutive numbers. 2,4,6,8 are ______ numbers.

This is actually for a math question. I see questions asking about "consecutive even numbers" or "consecutive odd numbers", but how would one, in a similar manner, describe the general case of integers with a difference of two.

I'm hoping for a general word, which could also be applied as, for example:

Sunday, Tuesday, Thursday, Saturday is a series of _______ days.

• You would say "all numbers with remainder X modulo Y". Where Y is equal to 1 + the number of integers you want to leave out. This is really a math question, not an English one. Mar 15, 2016 at 15:54
• They are alternate numbers / days. Mar 15, 2016 at 15:59
• I've edited my question. I could describe the situation differently, but I was hoping there's a word I'm just not thinking of. Mar 15, 2016 at 16:00
• Re: your edit, there is no such word. That is not how language works. We do not have a dedicated adjective for every possible number of integers you can skip. No language has such a thing. Instead you would say "every Xth day starting with Sunday". Now that works in absolutely every language. Mar 15, 2016 at 16:00
• @RegDwigнt We do have a lot of words which take numerical prefixes (bi, tri, quad, sesqui ). I was hoping for something similar, although you may well be right about it not existing. Mar 15, 2016 at 16:22

## 3 Answers

In any sequence of one-in one-out, such as your examples of numbers or days, the elements are described as alternate.

What do you think about every other? It's not one word, but I could use it with only slight modification.

Sunday, Tuesday, Thursday, Saturday is a series consisting of ever other day.

or

Please pick up every other egg from that row.

• The nice thing about this approach is it also allows for "every third", "every fourth" and so on. Mar 15, 2016 at 17:12

Interspersed.

intersperse

[in-ter-spurs]

verb (used with object), interspersed, interspersing.

1. to scatter here and there or place at intervals among other things: to intersperse flowers among shrubs.
2. to diversify with something placed or scattered at intervals: to intersperse a dull speech with interesting anecdotes.
• Interesting angle of approach, but sadly doesn't work. ‘Interspersed numbers’ doesn't mean anything and would, with 99% certainty, not be understood. Mar 15, 2016 at 17:24
• "Interspersed numeric values" is more concise. Mar 15, 2016 at 18:06
• Here is the alphabet with interspersed numeric values: "a b c d 1 45 e f 8 g 72 h 9 i j k 34 l m 7 23 n o p 53 q 21 6 r s t 45 u 10 v 11 w 43 x y 14 z"
– Jim
Mar 16, 2016 at 1:45