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A363079
The sum of the digits present in a(n) and a(n+1) divides exactly a(n). This is the lexicographically earliest infinite sequence of distinct positive terms having this property.
0
10, 13, 18, 27, 99, 69, 17, 36, 12, 21, 22, 16, 45, 15, 54, 63, 39, 999, 19, 72, 30, 25, 189, 81, 198, 31, 1899, 499999999999999999999
OFFSET
1,1
COMMENTS
If we want the sequence to be infinite, we cannot extend it with terms < 10. After a(28) = 499999999999999999999 the terms become exponentially huge and impossible to present here.
LINKS
EXAMPLE
digitsum a(1) + digitsum a(2) = 1 + 0 + 1 + 3 = 5 and 5 divides exactly a(1) = 10;
digitsum a(2) + digitsum a(3) = 1 + 3 + 1 + 8 = 13 and 13 divides exactly a(2) = 13;
digitsum a(3) + digitsum a(4) = 1 + 8 + 2 + 7 = 18 and 18 divides exactly a(3) = 18;
digitsum a(4) + digitsum a(5) = 2 + 7 + 9 + 9 = 27 and 27 divides exactly a(4) = 27;
digitsum a(5) + digitsum a(6) = 9 + 9 + 6 + 9 = 33 and 33 divides exactly a(5) = 99; etc.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Eric Angelini, Jul 13 2023
STATUS
approved