A269315 Numbers x that are the sum of the digits of some consecutive run of numbers x-1, x-2, x-3, ...

3, 12, 15, 21, 24, 30, 33, 42, 51, 60, 69, 120, 135, 144, 150, 159, 168, 177, 186, 195, 210, 237, 243, 258, 267, 291, 300, 333, 342, 357, 372, 423, 447, 468, 492, 513, 540, 558, 579, 594, 603, 630, 645, 654, 660, 675, 720, 735, 747, 777, 792, 810, 825, 837, 873

Offset

1,1

Comments

All terms are multiples of 3.

Links

Paolo P. Lava, Table of n, a(n) for n = 1..1000

Example

3 = 2 + 1;
12 = 1+1 + 1+0 + 9;
15 = 1+4 + 1+3 + 1+2 + 1+1 + 1+0.

Maple

P:= proc(q) local a, b, c, k, n; for n from 1 to q do a:=0; b:=0;
while a<n do b:=b+1; c:=n-b; for k from 1 to ilog10(n-b)+1 do a:=a+(c mod 10); c:=trunc(c/10);
od; od; if a=n then print(n); fi; od; end: P(10^6);

Mathematica

Select[Range[3, 1000], (x = # - 1; s = Total[IntegerDigits[x]]; While[s < #, x--; s += Total[IntegerDigits[x]]]; s == #) &] (* Robert Price, May 22 2019 *)

Crossrefs

Cf. A269314.

Sequence in context: A287357 A044828 A248105 * A329575 A022380 A331074

Adjacent sequences: A269312 A269313 A269314 * A269316 A269317 A269318

Keyword

nonn,base,easy

Author

Paolo P. Lava, Feb 25 2016

Status

approved