A147823 Minimum number k for which the digital sum of k*n is 3*n.

0, 3, 3, 3, 12, 39, 33, 57, 111, 111, 3999, 3909, 2499, 3846, 6357, 33333, 43743, 52347, 111111, 310521, 3999999, 947619, 3090909, 3473913, 16666662, 39999999, 34576923, 37037037, 246428571, 310337931, 3333333333, 2193516129, 6249999684, 33303030303

Offset

0,2

Links

Chai Wah Wu, Table of n, a(n) for n = 0..49

Maple

P:=proc(i) local j, k, n, ok, w; for n from 0 by 1 to i do j:=-1; ok:=1; while ok=1 do j:=j+1; w:=0; k:=n*j; while k>0 do w:=w+k-(trunc(k/10)*10); k:=trunc(k/10); od; if w=3*n then ok:=0; print(j); fi; od; od; end: P(100);

Mathematica

dskn[n_]:=Module[{k=0}, While[Total[IntegerDigits[k*n]]!=3n, k++]; k]; Array[dskn, 20, 0] (* Harvey P. Dale, Sep 14 2012 *)

Prog

(PARI) a(n) = {my(k = 0); while (sumdigits(k*n) != 3*n, k++); k; }; \\ Michel Marcus, Mar 21 2016

Crossrefs

Cf. A147822, A147824-A147831.

Sequence in context: A052900 A024947 A291407 * A341211 A335518 A269347

Adjacent sequences: A147820 A147821 A147822 * A147824 A147825 A147826

Keyword

easy,nonn,base

Author

Paolo P. Lava and Giorgio Balzarotti, Nov 14 2008

Extensions

Edited by Charles R Greathouse IV, Nov 01 2009

a(20)-a(33) from Donovan Johnson, Sep 16 2012

Status

approved