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A181958
Number of distinct values that can be generated by an expression containing n binary operators (any of add, subtract, multiply and divide) whose operands are any integer between 1 and 9; parenthesis allowed.
5
9, 93, 931, 11644, 126436, 1443224
OFFSET
0,1
EXAMPLE
a(1) = 93 and the distinct values are -8, -7, -6, -5, -4, -3, -2, -1, 1/9, 1/8, 1/7, 1/6, 1/5, 2/9, 1/4, 2/7, 1/3, 3/8, 2/5, 3/7, 4/9, 1/2, 5/9, 4/7, 3/5, 5/8, 2/3, 5/7, 3/4, 7/9, 4/5, 5/6, 6/7, 7/8, 8/9, 1, 9/8, 8/7, 7/6, 6/5, 5/4, 9/7, 4/3, 7/5, 3/2, 8/5, 5/3, 7/4, 9/5, 2, 9/4, 7/3, 5/2, 8/3, 3, 7/2, 4, 9/2, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 21, 24, 25, 27, 28, 30, 32, 35, 36, 40, 42, 45, 48, 49, 54, 56, 63, 64, 72, 81
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Derek M. Jones, Apr 03 2012
STATUS
approved