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A334737
Lexicographically earliest sequence of distinct positive integers such that the digital root of a(n+1) divides a(n).
2
1, 10, 2, 11, 19, 28, 4, 13, 37, 46, 20, 5, 14, 7, 16, 8, 17, 55, 23, 64, 22, 29, 73, 82, 38, 47, 91, 25, 32, 26, 56, 31, 100, 40, 35, 34, 65, 41, 109, 118, 74, 83, 127, 136, 44, 49, 43, 145, 50, 59, 154, 52, 58, 92, 67, 163, 172, 76, 85, 68, 94, 101, 181, 190, 77, 61, 199
OFFSET
1,2
LINKS
EXAMPLE
a(1) = 1 is divisible by the digital root of 10 (which is 1 + 0 = 1);
a(2) = 10 is divisible by the dig. root of 2 (which is = 2);
a(3) = 2 is divisible by the dig. root of 11 (which is 1 + 1 = 2);
a(4) = 11 is divisible by the dig. root of 19 (which is 1 + 9 = 10 => 1 + 0 = 1);
a(5) = 19 is divisible by the dig. root of 28 (which is 2 + 8 = 10 => 1 + 0 = 1);
a(6) = 28 is divisible by the dig. root of 4 (which is = 4); etc.
CROSSREFS
Cf. A248025, A334837 (same idea, but digital sum instead of digital root in the Name section).
Sequence in context: A257277 A248024 A269631 * A334837 A327689 A317387
KEYWORD
base,nonn
AUTHOR
Eric Angelini and Carole Dubois, May 09 2020
STATUS
approved