A377565 a(n) is the least multiple of n with more decimal digits than n.

10, 10, 12, 12, 10, 12, 14, 16, 18, 100, 110, 108, 104, 112, 105, 112, 102, 108, 114, 100, 105, 110, 115, 120, 100, 104, 108, 112, 116, 120, 124, 128, 132, 102, 105, 108, 111, 114, 117, 120, 123, 126, 129, 132, 135, 138, 141, 144, 147, 100, 102, 104, 106, 108

Offset

1,1

Links

Rémy Sigrist, Table of n, a(n) for n = 1..9999

Formula

a(n) = n * A097327(n).

Example

For n = 42: 42 and 2*42 have the same number of digits, while 3*42 has more digits, so a(42) = 3*42 = 126.

Mathematica

Table[n*Ceiling[10^IntegerLength[n]/n], {n, 120}] (* Michael De Vlieger, Nov 02 2024 *)

Prog

(PARI) a(n) = n * ceil(10^#digits(n) / n)
(Python)
def A377565(n): return n-1+10**(l:=len(str(n)))-(pow(10, l, n)-1)%n # Chai Wah Wu, Nov 02 2024

Crossrefs

Cf. A055642, A097327, A109940.

Sequence in context: A215511 A280105 A173198 * A111381 A369604 A063660

Adjacent sequences: A377562 A377563 A377564 * A377566 A377567 A377568

Keyword

nonn,base,easy

Author

Rémy Sigrist, Nov 01 2024

Status

approved