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A105448
Positive integers whose representation as Roman Fibonacci numbers has exactly three symbols.
4
17, 25, 27, 28, 30, 38, 40, 41, 43, 44, 45, 46, 48, 49, 51, 59, 61, 62, 64, 65, 66, 67, 69, 70, 71, 72, 73, 74, 75, 77, 78, 79, 82, 83, 85, 93, 95, 96, 98, 99, 100, 101, 103, 104, 105, 107, 108, 109, 111, 112, 113, 115, 118, 124, 125, 126, 128, 132, 133, 134, 136, 140
OFFSET
1,1
COMMENTS
A105446 gives the number of symbols in Roman Fibonacci numbers. A105447 gives positive integers whose representation as Roman Fibonacci numbers has exactly two symbols. A105449 gives positive integers whose representation as Roman Fibonacci numbers has exactly four symbols. A105450 gives positive integers whose representation as Roman Fibonacci numbers has exactly five symbols.
FORMULA
a(n) is an element of A105447 iff A105446(n) = 3.
EXAMPLE
In Roman Fibonacci number representation:
17 = "A22", 25 = "B22", 27 = "AA1", 28 = "AA2", 30 = "B81", 38 = "C22", 40 = "C33", 41 = "C52", 43 = "BB1", 44 = "BB2", 45 = "BB3", 46 = "1CA", 48 = "CA1", ..., 155 = "2FA", 156 = "1FA", 158 = "FA1", 159 = "FA2", 160 = "FA3".
KEYWORD
base,easy,nonn
AUTHOR
Jonathan Vos Post, Apr 09 2005
STATUS
approved