Strobogrammatic Numbers
A Strobogrammatic Number is a number that appears the same whether viewed normally or upside down. In base 10, given that 0, 1 and 8 are symmetrical around the horizontal axis, and 6 and 9 are the same as each other upside down, the first few strobogrammatic numbers are:
1, 8, 11, 69, 88, 96, 101,
111, 181, 609, 619, 689, 808,
818, 888, 906, 916, 986, 1001
What years are strobogrammatic?
More Numbers at www.TheMathWebSite.com.
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