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A326740
Numbers which converge to 7 under repeated application of the powertrain map of A133500.
10
7, 71, 75, 107, 117, 127, 137, 147, 157, 167, 177, 187, 197, 207, 307, 407, 507, 523, 543, 607, 707, 711, 723, 747, 751, 807, 907, 1071, 1075, 1171, 1175, 1271, 1275, 1371, 1375, 1471, 1475, 1571, 1575, 1671, 1675, 1771, 1775, 1871, 1875, 1971, 1975, 2071
OFFSET
1,1
EXAMPLE
75 -> 7^5 = 16807 -> 1^6*8^0*7 = 7.
KEYWORD
nonn,base,easy
AUTHOR
Martin Renner, Jul 22 2019
STATUS
approved