A136603 Positive numbers having a unique representation by inserting minus and plus-signs in 123456789.
176, 191, 194, 196, 209, 213, 215, 217, 223, 237, 253, 259, 263, 272, 274, 275, 289, 290, 292, 293, 295, 305, 307, 308, 353, 361, 367, 379, 380, 381, 382, 386, 392, 399, 401, 405, 415, 416, 418, 419, 427, 443, 461, 463, 467, 475, 477, 479, 481, 490, 491
Offset: 1
Examples
a(1) = 176 = 1 - 2 + 34 + 56 + 78 + 9; a(2) = 191 = 123 + 4 + 56 + 7 - 8 + 9; a(3) = 194 = 1 - 2 + 34 + 5 + 67 + 89; a(4) = 196 = -1 + 2 + 34 + 5 + 67 + 89; a(5) = 209 = 1 + 234 + 56 + 7 - 89; a(6) = 213 = 123 + 4 + 5 - 6 + 78 + 9; a(7) = 215 = 123 + 4 - 5 + 6 + 78 + 9; a(8) = 217 = 123 - 4 + 5 + 6 + 78 + 9; a(9) = 223 = -1 + 23 + 45 + 67 + 89; a(10) = 237 = -123 + 456 - 7 - 89; a(11) = 253 = -1 + 2 + 345 - 6 - 78 - 9; a(12) = 259 = -1 + 234 - 56 - 7 + 89; a(869) = 123456789 = A136602(1715).
Links
- R. Zumkeller, Table of n, a(n) for n = 1..869 (full sequence)
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