A332046 a(n) is the smallest positive integer such that there exist exactly n positive integers less than a(n) whose digital sum in base 10 is equal to the digital sum of a(n).

10, 20, 30, 40, 50, 60, 70, 80, 90, 108, 117, 126, 135, 144, 153, 162, 171, 180, 207, 216, 225, 234, 243, 252, 261, 270, 280, 307, 316, 325, 334, 343, 352, 361, 370, 406, 415, 424, 433, 442, 451, 460, 470, 506, 515, 524, 533, 542, 551, 560, 605, 614, 623, 632, 641, 650, 660

Offset: 1

Author

Arnauld Chevallier, Feb 06 2020

Keywords

• nonn
• base

Examples

			For n=10, 108 is the smallest positive integer for which there exists exactly 10 smaller integers whose digit sum in base 10 is the same as the digit sum of 108 (i.e., 1+0+8=9). These integers are 9, 18, 27, 36, 45, 54, 63, 72, 81, 90.
		

Crossrefs

Cf. A081926 (similar but different definition).

Programs

PARI

isok(k, n) = {my(v=vector(k, j, sumdigits(j))); #select(x->(x==v[k]), v) == n+1;}
a(n) = {my(k=1); while(! isok(k, n), k++); k;} \\ Michel Marcus, Feb 16 2020