A334837 The digital sum of a(n+1) divides a(n). This is the lexicographically earliest sequence of positive distinct terms with this property.

1, 10, 2, 11, 29, 100, 4, 13, 49, 7, 16, 8, 17, 89, 1000, 5, 14, 20, 19, 199, 10000, 22, 38, 101, 100000, 23, 599, 1000000, 26, 58, 110, 28, 25, 32, 31, 4999, 10000000, 35, 34, 98, 43, 79999, 100000000, 37, 19999, 52, 40, 41, 59999, 1000000000, 44, 47, 299999, 61

Offset

1,2

Comments

The prime terms of the sequence can be divided only by 1 and themselves. Hence the huge numbers.

Links

Carole Dubois, Table of n, a(n) for n = 1..310

Example

a(1) = 1 is divisible by the digital sum of a(2) = 10 as 1 + 0 = 1;
a(2) = 10 is divisible by the digital sum of a(3) = 2 which is 2;
a(3) = 2 is divisible by the digital sum of a(4) = 11 as 1 + 1 = 2;
a(4) = 11 is divisible by the digital sum of a(5) = 29 as 2 + 9 = 11; etc.

Crossrefs

Cf. A334737 (digital root instead of digital sum).

Sequence in context: A248024 A269631 A334737 * A327689 A317387 A303784

Adjacent sequences: A334834 A334835 A334836 * A334838 A334839 A334840

Keyword

base,nonn

Author

Eric Angelini and Carole Dubois, May 13 2020

Status

approved