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Demonstration of the
On-Line Encyclopedia of Integer Sequences® (OEIS®)
Identifying a Sequence: a Puzzle
In this next example you could be anyone in the world who uses Arabic numerals - a primary school student in England studying for an I.Q. test or a businessman in India reading the puzzle column of a newspaper.
You are asked to explain this sequence and find the next term:
You decide to ask the OEIS for help.
As in the previous two demonstrations, you go to the main web page and enter the sequence.
This produces the following response.
Greetings from the On-Line Encyclopedia of Integer Sequences!
Ah yes, 61 is 16 = 4 x 4 written backwards!
Other sequences from tests and quizzes can be found in the Puzzle sequences web page (but then you will have to use the Back button on your browser to return to these demonstrations). Of course many others can be found by using the webcam to browse the OEIS.
Click the single right arrow to go to the next demonstration page, or the single left arrow to return to the previous page.