A364578 a(n) is the smallest n-digit number whose sum of digits is n.

1, 11, 102, 1003, 10004, 100005, 1000006, 10000007, 100000008, 1000000009, 10000000019, 100000000029, 1000000000039, 10000000000049, 100000000000059, 1000000000000069, 10000000000000079, 100000000000000089, 1000000000000000099, 10000000000000000199

Offset

1,2

Links

Michael S. Branicky, Table of n, a(n) for n = 1..1000

Mathematica

Table[Module[{t=10^n}, While[Total[IntegerDigits[t]]!=n+1, t++]; t], {n, 0, 20}] (* or *) Join[{1}, 10^Range[63]+Flatten[Table[(k+1) 10^n-1, {n, 0, 6}, {k, 9}]]] (* Harvey P. Dale, Mar 31 2024 *)

Prog

(PARI) a(n) = my(k=10^(n-1)); while (sumdigits(k) != n, k++); k; \\ Michel Marcus, Aug 16 2023
(Python)
def a(n): m=(n-1)//9; return int("1"+"0"*(n-m-2)+str((n-1)%9)*(n>1)+"9"*m)
print([a(n) for n in range(1, 21)]) # Michael S. Branicky, Aug 16 2023

Crossrefs

Cf. A051885, A202270 (largest instead of smallest).

Sequence in context: A048441 A099294 A081552 * A156948 A287302 A141915

Adjacent sequences: A364575 A364576 A364577 * A364579 A364580 A364581

Keyword

nonn,base,easy

Author

Roland Kneer, Aug 14 2023

Status

approved