A377422 Numbers that can be expressed as (m + sum of digits of m) in exactly four ways.

1000000000000000000000102, 1000000000000000000000104, 1000000000000000000000106, 1000000000000000000000108, 1000000000000000000000110, 1000000000000000000000112, 1000000000000000000000114, 100000000000000000000000116, 100000000000000000000000118

Offset

1,1

Comments

Let f(n) = n + (sum of digits of n) = A062028(n).

Let g(m) = number of n such that f(n) = m (i.e. the number of inverses of m), A230093(m).

Numbers m with g(m) = 0 are called the Self or Colombian numbers, A003052.

Numbers m with g(m) = 1 give A225793.

Numbers m with g(m) = 2 give A230094.

Numbers m with g(m) = 3 give A230100.

The present sequence gives numbers m such that A230093(m) = 4.

Links

Daniel Mondot, Table of n, a(n) for n = 1..10000

Example

There are exactly four numbers, 999999999999999999999894, 999999999999999999999903, 1000000000000000000000092, and 1000000000000000000000101, whose image under n->f(n) is 1000000000000000000000104, so 1000000000000000000000104 is a member of the sequence.

Crossrefs

Cf. A230100, A006064, A062028, A230093.

Sequence in context: A257374 A217422 A328860 * A095442 A332605 A130682

Adjacent sequences: A377419 A377420 A377421 * A377423 A377424 A377425

Keyword

nonn,base

Author

Daniel Mondot, Oct 27 2024

Status

approved