# 101

This number is a prime.

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The 5th centered decagonal number (numbers of the form 5(n^2 - n) + 1). [Green]

Something 101 (pronounced 'one-oh-one') in popular slang is the beginning or introductory lessons required for any understanding, as in 'Home Buying 101' or 'Prime Numbers 101'. [Green]

101 (base b) is a near-square number in every base b and it is conjectured that there are infinitely many bases for which 101 is prime. [Green]

POWERS OF 101 - PASCALINDROMES
The first five consecutive powers of 101 produce
palindromes. The next 4 consecutive powers of 101
produce 'quasi-palindromes' in the sense of
concatenating several multidigit numbers in reverse
order, but not reversing the digits of those individual
numbers. In all these powers the numbers in the rows
of Pascal's Triangle can be seen in order (with some
zeros thrown in here and there so that each number,
after the first, occupies a two-digit space), hence the
name 'Pa-sca-lindromes'.
1010 = 1
1011 = 101
1012 = 10201
1013 = 1030301
1014 = 104060401
1015 = 10510100501
1016 = 1061520150601
1017 = 107213535210701
1018 = 10828567056280801
[Green]

(There is one curio for this number that has not yet been approved by an editor.)