A308393 "Autotomy numbers" have two properties: (1) they have distinct decimal digits, and (2) subtracting their last digit from the remaining part produces another autotomy number (the numbers 1 to 9 are considered to be part of the sequence).
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 21, 30, 31, 32, 40, 41, 42, 43, 50, 51, 52, 53, 54, 60, 61, 62, 63, 64, 65, 70, 71, 72, 73, 74, 75, 76, 80, 81, 82, 83, 84, 85, 86, 87, 90, 91, 92, 93, 94, 95, 96, 97, 98, 210, 243, 254, 265, 276, 287, 298, 309, 310, 320, 321, 342, 354, 364, 365, 375, 376, 386, 387, 397, 398, 408, 409, 410, 419, 420, 421
Offset: 1
Examples
a(56) = 243 is in the sequence because 24-3 = 21 and 21 is already in the sequence. The same is true for a(57) = 254 as 25-4 = 21 too.
Links
- Jean-Marc Falcoz, Table of n, a(n) for n = 1..41943
- Eric Angelini, Pandigitaux et saucissons (in French).
Crossrefs
Cf. A308377 (autotomy numbers with 10 distinct decimal digits).
Comments